# Quiz 12: Inference About a Population

Statistics

Q 1Q 1

In order to determine the p-value associated with hypothesis testing about the population mean , it is necessary to know the value of the test statistic.

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True False

True

Q 2Q 2

In order to interpret the p-value associated with hypothesis testing about the population mean , it is necessary to know the value of the test statistic.

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True False

False

Q 3Q 3

If a sample has 15 observations and a 95% confidence estimate for is needed, the appropriate value of t is 1.753.

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True False

False

Q 4Q 4

If a sample has 18 observations and a 90% confidence estimate for is needed, the appropriate value of t is 1.740.

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True False

Q 5Q 5

The statistic when the sampled population is normal is Student t-distributed with n degrees of freedom.

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True False

Q 6Q 6

If the sampled population is nonnormal, the t-test of the population mean is still valid, provided that the condition is not extreme.

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True False

Q 7Q 7

A race car driver tested his car for time from 0 to 60 mph, and in 20 tests obtained an average of 48.5 seconds with a standard deviation of 1.47 seconds.A 95% confidence interval for the 0 to 60 time is 45.2 seconds to 51.8 seconds.

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True False

Q 8Q 8

In forming a 95% confidence interval for a population mean from a sample size of 20, the number of degrees of freedom from the t-distribution equals 20.

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True False

Q 9Q 9

The t-distribution is used in a confidence interval for a mean when the actual standard error is not known.

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True False

Q 10Q 10

The t-distribution allows the calculation of confidence intervals for means for small samples when the population variance is not known, regardless of the shape of the distribution in the population.

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True False

Q 11Q 11

The t-distribution is used to develop a confidence interval estimate of the population mean when the population standard deviation is unknown.

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True False

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True False

Q 13Q 13

In estimating the population mean with the population standard deviation unknown, if the sample size is 16, there are 8 degrees of freedom.

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True False

Q 14Q 14

For statistical inference about the mean of a single population when the population standard deviation is unknown, the degrees for freedom for the t-distribution equal n 1 because we lose one degree of freedom by using the:
A) sample mean as an estimate of the population mean.
B) sample standard deviation as an estimate of the population standard deviation.
C) sample proportion as an estimate of the population proportion.
D) sample size as an estimate of the population size.

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Multiple Choice

Q 15Q 15

A robust estimator is one that is:
A) unbiased and symmetrical about zero.
B) consistent and is also mound-shaped.
C) efficient and less spread out.
D) not sensitive to moderate nonnormality.

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Multiple Choice

Q 16Q 16

A random sample of size 15 taken from a normally distributed population revealed a sample mean of 75 and a sample variance of 25.The upper limit of a 95% confidence interval for the population mean would equal:
A) 77.77
B) 72.23
C) 88.85
D) 77.27

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Multiple Choice

Q 17Q 17

A major electronics store chain is interested in estimating the average amount its credit card customers spent on their first visit to the chain's new store in the mall.Fifteen credit card accounts were randomly sampled and analyzed with the following results: = $50.50 and s

^{2}= 400.A 95% confidence interval for the average amount the credit card customers spent on their first visit to the chain's new store in the mall is: A) $50.50 $9.09. B) $50.50 $10.12. C) $50.50 $11.08. D) None of these choices.Free

Multiple Choice

Q 18Q 18

Researchers determine that 60 Puffs tissues is the average number of tissues used during a cold.Suppose a random sample of 100 Puffs users yielded the following data on the number of tissues used during a cold: = 52 and s = 22.Using the sample information provided, the value of the test statistic is:
A) t = (52 60) / 22
B) t = (52 60) / (22 / 100)
C) t = (52 60) / (22 / 100

^{2}) D) t = (52 60) / (22 / 10)Free

Multiple Choice

Q 19Q 19

For a 99% confidence interval of the population mean based on a sample of n = 25 with s = 0.05, the critical value of t is:
A) 2.7969
B) 2.7874
C) 2.4922
D) 2.4851

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Multiple Choice

Q 20Q 20

Based on sample data, the 90% confidence interval limits for the population mean are LCL = 170.86 and UCL = 195.42.If the 10% level of significance were used in testing the hypotheses H

_{0}: = 201 vs.H_{1}: 201, the null hypothesis: A) would be rejected. B) would be accepted. C) would fail to be rejected. D) would become H_{0}: 201Free

Multiple Choice

Q 21Q 21

The degrees of freedom for the test statistic for when is unknown is:
A) 1
B) n
C) n 1
D) None of these choices.

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Multiple Choice

Q 22Q 22

Researchers determined that 60 Puffs tissues is the average number of tissues used during a cold.Suppose a random sample of 100 Puffs users yielded the following data on the number of tissues used during a cold: = 52 and s = 22.Suppose the alternative we wanted to test was H

_{1}: < 60.The correct rejection region for = 0.05 is: A) reject H_{0}if t > 1.6604. B) reject H_{0}if t < 1.6604. C) reject H_{0}if t > 1.9842 or Z < 1.9842. D) reject H_{0}if t < 1.9842.Free

Multiple Choice

Q 23Q 23

When the population standard deviation is ____________________ and the population is normal, the test statistic for testing hypotheses about is the t-distribution with n 1 degrees of freedom.

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Essay

Q 24Q 24

When the population standard deviation is unknown and the population is ____________________, the test statistic for testing hypotheses about is the t-distribution with n 1 degrees of freedom.

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Q 25Q 25

When the population standard deviation is unknown and the population is normal, the test statistic for testing hypotheses about is the ____________________-distribution with ____________________ degrees of freedom.

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Q 26Q 26

The t-test for a population mean is ____________________, meaning that if the population is nonnormal, the results of the test and confidence interval are still valid as long as the nonnormality is not extreme.

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Q 27Q 27

When a population is small, we must adjust the test statistic and interval estimator using the ____________________ population correction factor.

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Q 28Q 28

____________________ populations allow us to use the confidence interval estimate of a mean to produce a confidence interval estimate of the population total.

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Q 29Q 29

The t-statistic has two variables: the sample ____________________ and the sample ____________________.

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Q 30Q 30

Because of the greater uncertainty, the t-statistic will display greater ____________________ than the z-statistic.

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Q 31Q 31

Single Mothers' Ages
A random sample of 10 single mothers was drawn from a Obstetrics Clinic.Their ages are 22, 17, 27, 20, 23, 19, 24, 18, 19, and 24 years.
-{Single Mothers' Ages Narrative} Estimate the population mean with 90% confidence.

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Q 32Q 32

Single Mothers' Ages
A random sample of 10 single mothers was drawn from a Obstetrics Clinic.Their ages are 22, 17, 27, 20, 23, 19, 24, 18, 19, and 24 years.
-{Single Mothers' Ages Narrative} Test to determine if we can infer at the 5% significance level that the population mean is not equal to 20.

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Q 33Q 33

Single Mothers' Ages
A random sample of 10 single mothers was drawn from a Obstetrics Clinic.Their ages are 22, 17, 27, 20, 23, 19, 24, 18, 19, and 24 years.
-{Single Mothers' Ages Narrative} What is the required condition of the techniques used in the previous questions? What graphical device can you use to check to see if that required condition is satisfied?

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Essay

Q 34Q 34

Concert Tickets
A simple random sample of 100 concert tickets was drawn from a normal population.The mean and standard deviation of the sample were $120 and $25, respectively.
-{Concert Tickets Narrative} Test the hypothesis H

_{0}: = 125 vs.H_{1}: 125 at the 10% significance level.Free

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Q 35Q 35

Concert Tickets
A simple random sample of 100 concert tickets was drawn from a normal population.The mean and standard deviation of the sample were $120 and $25, respectively.
-{Concert Tickets Narrative} Estimate the population mean with 90% confidence.

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Q 36Q 36

Concert Tickets
A simple random sample of 100 concert tickets was drawn from a normal population.The mean and standard deviation of the sample were $120 and $25, respectively.
-{Concert Tickets Narrative} Explain how to use the confidence interval to test the hypotheses at = 0.10.

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Q 37Q 37

Hourly Fees
A random sample of 15 hourly fees for car washers (including tips) was drawn from a normal population.The sample mean and sample standard deviation were = $14.9 and s = $6.75.
-{Hourly Fees Narrative} Can we infer at the 5% significance level that the mean fee for car washers (including tips) is greater than 12?

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Q 38Q 38

Hourly Fees
A random sample of 15 hourly fees for car washers (including tips) was drawn from a normal population.The sample mean and sample standard deviation were = $14.9 and s = $6.75.
-{Hourly Fees Narrative} Can we infer at the 5% significance level that the population mean is greater than 12, assuming that you know the population standard deviation is equal to 6.75?

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Essay

Q 39Q 39

Tire Rotation
The manager of a service station is in the process of analyzing the number of times car owners rotate the tires on their cars.She believes that the average motorist rotates his or her car's tires less frequently than recommended by the owner's manual (two times per year).In a preliminary survey she asked 14 car owners how many times they rotated their cars' tires in the last 12 months.The results are 1, 1, 2, 0, 3, 3, 0, 1, 0, 1, 2, 3, 3, and 1.
-{Tire Rotation Narrative} Does this data provide sufficient evidence at the 10% significance level to indicate that the manager is correct?

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Q 40Q 40

Tire Rotation
The manager of a service station is in the process of analyzing the number of times car owners rotate the tires on their cars.She believes that the average motorist rotates his or her car's tires less frequently than recommended by the owner's manual (two times per year).In a preliminary survey she asked 14 car owners how many times they rotated their cars' tires in the last 12 months.The results are 1, 1, 2, 0, 3, 3, 0, 1, 0, 1, 2, 3, 3, and 1.
-{Tire Rotation Narrative} What condition is required in order to analyze this data using a t-test?

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Q 41Q 41

Tire Rotation
The manager of a service station is in the process of analyzing the number of times car owners rotate the tires on their cars.She believes that the average motorist rotates his or her car's tires less frequently than recommended by the owner's manual (two times per year).In a preliminary survey she asked 14 car owners how many times they rotated their cars' tires in the last 12 months.The results are 1, 1, 2, 0, 3, 3, 0, 1, 0, 1, 2, 3, 3, and 1.
-The air pumps at service stations come equipped with a gauge to regulate the air pressure of tires.A mechanic believes that the gauges are in error by at least 3 pounds per square inch.To test his belief he takes a random example of 50 air pump gauges and determines the difference between the true pressure (as measured by an accurate measuring device) and the pressure shown on the air pump gauge.The mean and the standard deviation of the sample are = 3.4 and s = 1.2.Can the mechanic infer that he is correct at the 5% significance level? Assume tire pressures have a normal distribution.

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Essay

Q 42Q 42

Tire Rotation
The manager of a service station is in the process of analyzing the number of times car owners rotate the tires on their cars.She believes that the average motorist rotates his or her car's tires less frequently than recommended by the owner's manual (two times per year).In a preliminary survey she asked 14 car owners how many times they rotated their cars' tires in the last 12 months.The results are 1, 1, 2, 0, 3, 3, 0, 1, 0, 1, 2, 3, 3, and 1.
-A life insurance representative believes that the mean age of people who buy their first life insurance plan is less than 35.To test his belief he takes a random sample of 15 customers who have just purchased their first life insurance.Their ages are 42, 43,28, 34, 30, 36, 25, 29, 32, 33, 27, 30, 22, 37, and 40.There is not enough evidence to say the data are nonnormal.Can we conclude at the 1% significance level that the insurance representative is correct?

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Essay

Q 43Q 43

Mystic Pizza
Mystic Pizza in Mystic, Connecticut, advertises that they deliver your pizza within 15 minutes of placing an order or it is free.A sample of 25 customers is selected at random.The average delivery time in the sample was 13 minutes with a sample standard deviation of 4 minutes.
-{Mystic Pizza Narrative} We want to know whether Mystic can make this claim or not.Test to determine if we can infer at the 5% significance level that the population mean delivery time is less than 15 minutes.

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Q 44Q 44

Mystic Pizza
Mystic Pizza in Mystic, Connecticut, advertises that they deliver your pizza within 15 minutes of placing an order or it is free.A sample of 25 customers is selected at random.The average delivery time in the sample was 13 minutes with a sample standard deviation of 4 minutes.
-{Mystic Pizza Narrative} What is the required condition of the technique used in the previous question?

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Essay

Q 45Q 45

Energy Drink Consumption
A researcher at the University of Washington medical school believes that energy drink consumption may increase heart rate.Suppose it is known that heart rate (in beats per minute) is normally distributed with an average of 70 bpm for adults.A random sample of 25 adults was selected and it was found that their average heartbeat was 73 bpm after energy drink consumption, with a standard deviation of 7 bpm.
-{Energy Drink Consumption Narrative} Formulate the null and alternative hypotheses.

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Q 46Q 46

Energy Drink Consumption
A researcher at the University of Washington medical school believes that energy drink consumption may increase heart rate.Suppose it is known that heart rate (in beats per minute) is normally distributed with an average of 70 bpm for adults.A random sample of 25 adults was selected and it was found that their average heartbeat was 73 bpm after energy drink consumption, with a standard deviation of 7 bpm.
-{Energy Drink Consumption Narrative} Test the hypotheses in the previous question at the 10% significance level to determine if we can infer that energy drink consumption increases heart rate.

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Q 47Q 47

Employees in a large company are entitled to 15-minute water breaks.A random sample of the duration of water breaks for 10 employees was taken with the times shown as: 12, 16, 14, 18, 21, 17, 19, 15, 18, and 16.Assuming that the times are normally distributed, is there enough evidence at the 5% significance level to indicate that on average employees are taking longer water breaks than they are entitled to?

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Essay

Q 48Q 48

During a natural gas shortage, a gas company randomly sampled residential gas meters in order to monitor daily gas consumption.On a particular day, a sample of 100 meters showed a sample mean of 250 cubic feet and a sample standard deviation of 50 cubic feet.Provide a 90% confidence interval estimate of the mean gas consumption for the population.

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Essay

Q 49Q 49

The chi-squared distribution can be used in constructing confidence intervals and carrying out hypothesis tests regarding the value of a population variance.

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True False

Q 50Q 50

A condition of using the chi-squared test statistic for testing the variance is that the population random variable have a normal distribution.

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True False

Q 51Q 51

A left-tailed area in the chi-squared distribution equals 0.95.For 6 degrees of freedom the critical value equals 12.592.

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True False

Q 52Q 52

The area to the right of a certain critical value on a chi-squared distribution is 0.025.For 5 degrees of freedom, the critical value is 11.143.

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True False

Q 53Q 53

The test statistic used to test hypotheses about the population variance is given by

^{2}= (n 1)s^{2}/ ^{2}, which is chi-squared distributed with n 1 degrees of freedom when the population random variable is normally distributed with variance equal to ^{2}.Free

True False

Q 54Q 54

A random sample is drawn from a normal distribution with mean and variance

^{2}.The random variable (n 1)S^{2}/ ^{2 }has a chi-squared probability distribution with n degrees of freedom.Free

True False

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True False

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True False

Q 57Q 57

Which of the following is an example illustrating the use of variance?
A) As a measure of risk.
B) As a judge of consistency.
C) To search for and reduce variability in a process.
D) All of these choices are true.

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Multiple Choice

Q 58Q 58

A random sample of 25 observations is selected from a normally distributed population.The sample variance is 10.In the 95% confidence interval for the population variance, the upper limit is:
A) 19.353
B) 17.331
C) 17.110
D) 6.097

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Multiple Choice

Q 59Q 59

The statistic (n 1)s

^{2}/ ^{2}has a chi-squared distribution with n 1 degrees of freedom if: A) the sample has a Student t-distribution with degrees of freedom equal to n 1. B) the sample is normally distributed with variance equal to s^{2}. C) the population is normally distributed with variance equal to ^{2}. D) All of these choices are true.Free

Multiple Choice

Q 60Q 60

Which of the following conditions is needed regarding the chi-squared test statistic for the test of variance?
A) The population random variable must be normal.
B) The test statistic must be a non-negative number.
C) The test statistic must have a chi-squared distribution with n 1 degrees of freedom.
D) All of these choices are true.

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Multiple Choice

Q 61Q 61

In a hypothesis test for the population variance, the hypotheses are H

_{0}: ^{2}= 30 vs.H_{1}: ^{2}< 30.If the sample size is 20 and the test is being carried out at the 5% level of significance, the null hypothesis is rejected if: A) ^{2}< 30.144. B) ^{2}> 10.851. C) ^{2}< 10.117. D) ^{2}> 31.410.Free

Multiple Choice

Q 62Q 62

In a hypothesis test for the population variance, the hypotheses are H

_{0}: ^{2}= 100 vs.H_{1}: ^{2} 100.If the sample size is 15 and the test is being carried out at the 10% level of significance, the rejection region is: A) ^{2}< 6.571 or ^{2}> 23.685. B) ^{2}< 7.790 or ^{2}> 21.064. C) ^{2}< 8.547 or ^{2}> 22.307. D) ^{2}< 7.261 or ^{2}< 24.996.Free

Multiple Choice

Q 63Q 63

The sum of squared deviations from the mean divided by the population variance has a(n) ____________________ distribution with ____________________ degrees of freedom.

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Essay

Q 64Q 64

The test statistic used to test hypotheses about the population variance has a(n) ____________________ distribution with ____________________ degrees of freedom.

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Q 65Q 65

The test statistic to test hypotheses about the population variance has a chi-squared distribution with n 1 degrees of freedom when the population random variable has a(n) ____________________ distribution.

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Q 66Q 66

The chi-squared test and estimator of the population variance ____________________(are/are not) valid if the population is slightly to moderately nonnormal.

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Q 67Q 67

The test statistic used to test hypotheses about the population variance has a chi-squared distribution with ____________________ degrees of freedom.

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Q 68Q 68

The ____________________ confidence limit of the confidence interval estimator of the population variance is .

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Q 69Q 69

The ____________________ confidence limit of the confidence interval estimator of the population variance is .

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Q 70Q 70

If we are testing for an improvement in the consistency of an operation or the manufacturing of a product, the alternative hypothesis would have a(n) ____________________ sign in it.

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Q 71Q 71

An investor is concerned with the risk associated with a portfolio of stocks.He draws a random sample of nine monthly returns (expressed as a percentage of the initial investment).These data follow: 2, 5, 6, 10, 1, 2, 3, 0, and 7.Find a 95% confidence interval estimate of the population variance.

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Essay

Q 72Q 72

A pharmaceutical company has just developed a new capsule to alleviate the symptoms of allergies and colds.However, they are concerned about the variability in the amount of time until the drug becomes effective.In a random sample of 10 individuals who suffer from allergies, the amount of time (in hours) for the capsule to take effect was recorded and listed as follows: 5, 7, 6, 10, 9, 12, 8, 17, 4, and 16.Estimate with 90% confidence the variance of the time for the drug to become effective.

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Essay

Q 73Q 73

The sales manager of a large multinational corporation is concerned that some salespersons perform very well and others quite poorly.To help analyze the problem he draws a random sample of 20 salespersons, determines their commission incomes (in thousands of dollars), and calculates the following statistics: = $37.2, and s = $7.8.Do these statistics provide sufficient evidence at the 5% significance level to conclude that the population variance exceeds $35 million

^{2}?Free

Essay

Q 74Q 74

Applicants' Grades
The grades of a sample of 10 applicants, selected at random from a large population, are 71, 86, 75, 63, 92, 70, 81, 59, 80, and 90.
-{Applicants' Grades Narrative} Compute the sample variance.

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Q 75Q 75

Applicants' Grades
The grades of a sample of 10 applicants, selected at random from a large population, are 71, 86, 75, 63, 92, 70, 81, 59, 80, and 90.
-{Applicants' Grades Narrative} Construct a 90% confidence interval estimate for the population variance.

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Essay

Q 76Q 76

Applicants' Grades
The grades of a sample of 10 applicants, selected at random from a large population, are 71, 86, 75, 63, 92, 70, 81, 59, 80, and 90.
-{Applicants' Grades Narrative} Construct a 90% confidence interval estimate for the population standard deviation.

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Essay

Q 77Q 77

In determining the sample size needed to estimate the population proportion p, we let the sample proportion = 1 if we have no knowledge of even the approximate values of .

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True False

Q 78Q 78

The lower limit of the 90% confidence interval for the population proportion p, given that n = 400 and = 0.10, is 0.0247.

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True False

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True False

Q 80Q 80

In testing a hypothesis about a population proportion p, the z test statistic measures how close the computed sample proportion has come to the hypothesized population parameter.

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True False

Q 81Q 81

If we have some idea about the value of sample proportion , we use that value in determining the sample size needed to estimate the population proportion p.

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True False

Q 82Q 82

The 95% confidence interval would indicate that, for this shipment, the proportion of defective fuses is between 0 and 0.28.

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True False

Q 83Q 83

A professor of statistics refutes the claim that the proportion of Republican voters in Michigan is at most 44%.To test the claim, the hypotheses: H

_{0}: p = 0.44, H_{1}: p 0.44, should be used.Free

True False

Q 84Q 84

In selecting the sample size to estimate the population proportion p, if we have no knowledge of even the approximate values of the sample proportion , we:
A) take another sample and estimate.
B) take two more samples and find the average of their.
C) let= 0.50.
D) let= 0.95.

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Multiple Choice

Q 85Q 85

Under what condition(s) does the test statistic for p have an approximate normal distribution?
A) When np > 5.
B) When np and np(1 p) are both > 5.
C) When n > 30.
D) When np and n(1 p) are both > 5.

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Multiple Choice

Q 86Q 86

The use of the standard normal distribution for constructing confidence interval estimate for the population proportion p requires:
A) nand n(1 ) both greater than 5.
B) np and n(1 p) both greater than 5.
C) n(1 +) and n(1 ) both greater than 5.
D) sample size greater than 5.

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Multiple Choice

Q 87Q 87

After calculating the sample size needed to estimate a population proportion to within 0.04, your statistics professor told you the maximum allowable error must be reduced to just .01.If the original calculation led to a sample size of 800, the sample size will now have to be:
A) 800
B) 3,200
C) 6,400
D) 12,800

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Multiple Choice

Q 88Q 88

Assuming that all necessary conditions are met, what needs to be changed in the formula so that we can use it to construct a (1 ) confidence interval estimate for the population proportion p?
A) should be replaced by p.
B) t

_{}should be replaced by z_{}. C) t_{}should be replaced by t_{}_{ }_{/ 2}. D) t_{}should be replaced by z_{}_{ / 2}.Free

Multiple Choice

Q 89Q 89

The width of a confidence interval estimate for a proportion will be:
A) narrower for 90% confidence than for 95% confidence.
B) wider for a sample size of 100 than for a sample size of 50.
C) narrower for 99% confidence than for 95% confidence.
D) narrower when the sample proportion if 0.50 than when the sample proportion is 0.20.

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Multiple Choice

Q 90Q 90

When determining the sample size needed for a proportion for a given level of confidence and sampling error, the closer to 0.50 that p is estimated to be:
A) the smaller the sample size required.
B) the larger the sample size required.
C) the sample size is not affected.
D) the effect cannot be determined from the information given.

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Multiple Choice

Q 91Q 91

Which of the following would be an appropriate null hypothesis?
A) The population proportion is equal to 0.60.
B) The sample proportion is equal to 0.60.
C) The population proportion is not equal to 0.60.
D) All of these choices are true.

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Multiple Choice

Q 92Q 92

Which of the following would be an appropriate alternative hypothesis?
A) The population proportion is less than 0.65.
B) The sample proportion is less than 0.65.
C) The population proportion is equal to 0.65.
D) The sample proportion is equal to 0.65.

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Multiple Choice

Q 93Q 93

A survey claims that 9 out of 10 doctors recommend aspirin for their patients with headaches.To test this claim against the alternative that the actual proportion of doctors who recommend aspirin is less than 0.90, a random sample of 100 doctors' results in 83 who indicate that they recommend aspirin.The value of the test statistic in this problem is approximately equal to:
A) 1.67
B) 2.33
C) 1.86
D) 0.14

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Multiple Choice

Q 94Q 94

From a sample of 400 items, 14 are found to be defective.The point estimate of the population proportion defective will be:
A) 0.035
B) 0.05
C) 14
D) 28.57

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Multiple Choice

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Essay

Q 96Q 96

The test statistic for p is approximately normal when ____________________ and ____________________ are both greater than 5.

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Q 97Q 97

The test statistic for p is approximately normal when np and n(1 p) are both ____________________.

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Q 98Q 98

To test to see if the majority of the population exhibits a certain characteristic of interest, the alternative hypothesis of the test is H

_{1}: p ____________________.Free

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Q 99Q 99

When a population is small, it is necessary to include the ____________________ factor in our hypothesis tests and confidence interval estimators for p.

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Q 100Q 100

To produce a confidence interval estimator for the total, we multiply the lower and upper confidence limits of the interval estimator of p by ____________________.

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Q 102Q 102

The formula is used to find the sample size needed to estimate a population proportion.In this formula, B represents the ____________________ on the error of estimation.

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Q 103Q 103

Socialist Party Voters
A pollster in Italy wants to challenge a claim that 5% of the registered voters in his country are Socialists; he thinks the percentage is lower than that.In a test of hypothesis, H

_{0}: p = 0.05 vs.H_{1}: p < 0.05, his random sample of size 1,000 registered voters revealed that the number of Socialists was 40. -{Socialist Voters Narrative} Test the hypotheses at the 5% significance level.Free

Essay

Q 104Q 104

Socialist Party Voters
A pollster in Italy wants to challenge a claim that 5% of the registered voters in his country are Socialists; he thinks the percentage is lower than that.In a test of hypothesis, H

_{0}: p = 0.05 vs.H_{1}: p < 0.05, his random sample of size 1,000 registered voters revealed that the number of Socialists was 40. -{Socialist Voters Narrative} Compute the p-value and explain how to use it to test the hypotheses.Free

Essay

Q 105Q 105

Socialist Party Voters
A pollster in Italy wants to challenge a claim that 5% of the registered voters in his country are Socialists; he thinks the percentage is lower than that.In a test of hypothesis, H

_{0}: p = 0.05 vs.H_{1}: p < 0.05, his random sample of size 1,000 registered voters revealed that the number of Socialists was 40. -{Socialist Voters Narrative} Construct a 95% confidence interval estimate of the population proportion and explain how to use it to test the hypotheses.Free

Essay

Q 106Q 106

Physicians
A random sample of 200 physicians shows that there are 36 of them who make at least $400,000 a year.
-{Physicians Narrative} Can we conclude at the 1% significance level that the true proportion of physicians in the population who make at least $400,000 a year is less than 0.24?

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Q 107Q 107

Physicians
A random sample of 200 physicians shows that there are 36 of them who make at least $400,000 a year.
-{Physicians Narrative} Compute the p-value and explain how to use it to test the hypotheses.

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Q 108Q 108

Physicians
A random sample of 200 physicians shows that there are 36 of them who make at least $400,000 a year.
-{Physicians Narrative} Construct a 99% confidence interval estimate of the population proportion of physicians who make at least $400,000 a year, and explain how to use it to test the hypotheses.

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Essay

Q 109Q 109

Pilots' Union Contract
A union composed of several thousand pilots is preparing to vote on a new contract.A random sample of 500 pilots yielded 320 who planned to vote yes.It is believed that the new contract will receive more than 60% yes votes.
-{Pilots' Union Contract Narrative} State the appropriate null and alternative hypotheses.

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Q 110Q 110

Pilots' Union Contract
A union composed of several thousand pilots is preparing to vote on a new contract.A random sample of 500 pilots yielded 320 who planned to vote yes.It is believed that the new contract will receive more than 60% yes votes.
-{Pilots' Union Contract Narrative} Can we infer at the 5% significance level that the new contract will receive more than 60% yes votes?

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Q 111Q 111

Pilots' Union Contract
A union composed of several thousand pilots is preparing to vote on a new contract.A random sample of 500 pilots yielded 320 who planned to vote yes.It is believed that the new contract will receive more than 60% yes votes.
-{Pilots' Union Contract Narrative} Compute the p-value for the test.

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Q 112Q 112

New Mousetrap
After a financial analysis, the general manager of a large company decided that if more than 8% of potential buyers of a new mousetrap purchase that product, the company would show a profit.In a preliminary survey of 500 potential buyers, 56 people say that they will buy the mousetrap.
-{New Mousetrap Narrative} State the appropriate null and alternative hypotheses.

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Q 113Q 113

New Mousetrap
After a financial analysis, the general manager of a large company decided that if more than 8% of potential buyers of a new mousetrap purchase that product, the company would show a profit.In a preliminary survey of 500 potential buyers, 56 people say that they will buy the mousetrap.
-{New Mousetrap Narrative} Is there sufficient evidence at the 5% significance level that the mousetrap will produce a profit?

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Q 114Q 114

Sinus Drug
A company claims that 10% of the users of a certain sinus drug experience drowsiness.In clinical studies of this sinus drug, 81 of the 900 subjects experienced drowsiness
-{Sinus Drug Narrative} We want to test their claim and find out whether the actual percentage is not 10%.State the appropriate null and hypotheses.

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Q 115Q 115

Sinus Drug
A company claims that 10% of the users of a certain sinus drug experience drowsiness.In clinical studies of this sinus drug, 81 of the 900 subjects experienced drowsiness
-{Sinus Drug Narrative} Is there enough evidence at the 5% significance level to infer that the competitor is correct?

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Q 116Q 116

Sinus Drug
A company claims that 10% of the users of a certain sinus drug experience drowsiness.In clinical studies of this sinus drug, 81 of the 900 subjects experienced drowsiness
-{Sinus Drug Narrative} Compute the p-value of the test.

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Q 117Q 117

Sinus Drug
A company claims that 10% of the users of a certain sinus drug experience drowsiness.In clinical studies of this sinus drug, 81 of the 900 subjects experienced drowsiness
-{Sinus Drug Narrative} Construct a 95% confidence interval estimate of the population proportion of the users of this allergy drug who experience drowsiness.

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Q 118Q 118

Sinus Drug
A company claims that 10% of the users of a certain sinus drug experience drowsiness.In clinical studies of this sinus drug, 81 of the 900 subjects experienced drowsiness
-{Sinus Drug Narrative} Explain how to use this confidence interval to test the hypotheses.

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Q 119Q 119

As a manufacturer of guitars, a major corporation wants to estimate the proportion of guitar players who are right-handed.How many golfers must be surveyed if they want to be within 0.02, with a 95% confidence?
a.
Assume that there is no prior information that could be used as an estimate of.
b.
Assume that the manufacturer has an estimate offound from a previous study, which suggests that 75% of guitar players are right-handed.

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Q 120Q 120

In market segmentation, if education is the segmentation variable of interest, then possible segments of the market include: some high school, high school graduates, some college, college or university graduates.

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True False

Q 121Q 121

Market segmentation separates consumers of a product into different groups in such a way that members of each group are similar to each other and there are differences between groups.

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True False

Q 122Q 122

Mass Marketing refers to the mass production and marketing by a company of a single product for the entire market.

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True False

Q 123Q 123

Generally speaking, mass marketing has given way to target marketing, which focuses on satisfying the demands of a particular segment of the entire market.

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True False

Q 124Q 124

Mass marketing refers to the mass production and marketing by a company of all products the company produces for a single segment of the entire market.

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True False

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True False

Q 126Q 126

In estimating the total of a population of size N, where N is very large compared to the sample size, the confidence interval estimator of the total is .

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True False

Q 127Q 127

In estimating the population mean when the population size N is small, the confidence interval estimator of is .

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True False

Q 128Q 128

When is the finite population correction used?
A) When the population is more than or equal to 20 times the sample size.
B) When the population is less than or equal to 20 times the population size.
C) When the population is equal to 20 times the population size.
D) Whenever the sample size is small, no matter what the population size is.

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Multiple Choice

Q 129Q 129

If the lower and upper confidence limits of the population proportion p, using a sample of size 1500, are 0.184 and 0.238, respectively, then the lower and upper confidence limits of the total number of successes in the population, given that the population size is 750,000, are respectively:
A) 276 and 357
B) 137,724 and 178,143
C) 138,000 and 178,500
D) 138,276 and 179,857

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Multiple Choice

Q 130Q 130

Which of the following statements is correct regarding mass marketing?
A) It refers to the mass production and marketing by a company of a single product for the entire market.
B) It is especially effective for commodity goods such as gasoline, which are very difficult to differentiate from the competition, except through price and convenience of availability.
C) Generally speaking, mass marketing has given way to target marketing, which focuses on satisfying the demands of a particular segment of the entire market.
D) All of these choices are true.

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Multiple Choice

Q 131Q 131

If the lower and upper confidence limits of the population mean , using a sample of size 100, are 225 and 280, respectively, then the lower and upper confidence limits of the total of a population of size 3000 are respectively
A) 652,500 and 812,000
B) 675,000 and 840,000
C) 697,500 and 868,000
D) 652,862 and 812,452

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Multiple Choice

Q 132Q 132

Which of the following statements is false?
A) Because there is one single way to segment a market, managers must consider several variable or characteristics that could be used to identify segments.
B) Surveys of customers are used to gather data about various aspects of the market.
C) Statistical techniques are applied to the survey data to define the market segments.
D) Market segmentation separates consumers of a product into different groups in such a way that members of each group are similar to each other and there are differences between groups.

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Multiple Choice

Q 133Q 133

To estimate ____________________ when the population size N is small, the confidence interval estimator is .

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Q 134Q 134

____________________ refers to the mass production and marketing by a company of a single product for the entire market.

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Q 135Q 135

Mass marketing is especially effective for ____________________ goods such as gasoline, which are difficult to differentiate from the competition except through price and availability.

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Q 136Q 136

Marketing segmentation separates consumers of a product into different groups in such a way that members of each group are ____________________ and there are differences between ____________________.

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Q 137Q 137

When a population is small relative to the sample size, we must incorporate the ____________________ factor in the calculation of the standard error of estimate of the mean.

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Q 138Q 138

A population is defined to be small if it is ____________________ than ____________________ times the size of the sample.

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Q 139Q 139

Healthy Foods
In segmenting the frozen meal market in Spain, a food manufacturer uses health and diet consciousness as the segmentation variable.Four segments are developed and coded as follows:
To distinguish between groups, surveys are conducted.On the basis of a questionnaire, people are categorized as belonging to one of these groups.A recent survey asked a random sample of 1,500 Spanish adults (20 and over) to complete the survey.Out of the 1,500 people surveyed, 360 indicated that they are concerned about eating healthy foods.The most recent information available reveals that there are 40,256,000 Spanish adults who are 20 and over.
-{Healthy Foods Narrative} What is the objective of this problem?

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Q 140Q 140

Healthy Foods
In segmenting the frozen meal market in Spain, a food manufacturer uses health and diet consciousness as the segmentation variable.Four segments are developed and coded as follows:
To distinguish between groups, surveys are conducted.On the basis of a questionnaire, people are categorized as belonging to one of these groups.A recent survey asked a random sample of 1,500 Spanish adults (20 and over) to complete the survey.Out of the 1,500 people surveyed, 360 indicated that they are concerned about eating healthy foods.The most recent information available reveals that there are 40,256,000 Spanish adults who are 20 and over.
-{Healthy Foods Narrative} What is the parameter we wish to estimate? Explain.

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Q 141Q 141

Healthy Foods
In segmenting the frozen meal market in Spain, a food manufacturer uses health and diet consciousness as the segmentation variable.Four segments are developed and coded as follows:
To distinguish between groups, surveys are conducted.On the basis of a questionnaire, people are categorized as belonging to one of these groups.A recent survey asked a random sample of 1,500 Spanish adults (20 and over) to complete the survey.Out of the 1,500 people surveyed, 360 indicated that they are concerned about eating healthy foods.The most recent information available reveals that there are 40,256,000 Spanish adults who are 20 and over.
-{Healthy Foods Narrative} What is the point estimate of the proportion p of Spanish adults who classify themselves as concerned about eating healthy?

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Q 142Q 142

Healthy Foods
In segmenting the frozen meal market in Spain, a food manufacturer uses health and diet consciousness as the segmentation variable.Four segments are developed and coded as follows:
To distinguish between groups, surveys are conducted.On the basis of a questionnaire, people are categorized as belonging to one of these groups.A recent survey asked a random sample of 1,500 Spanish adults (20 and over) to complete the survey.Out of the 1,500 people surveyed, 360 indicated that they are concerned about eating healthy foods.The most recent information available reveals that there are 40,256,000 Spanish adults who are 20 and over.
-{Healthy Foods Narrative} Estimate with 95% confidence the proportion p of Spanish adults who classify themselves as concerned about eating healthy.

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Essay

Q 143Q 143

Healthy Foods
In segmenting the frozen meal market in Spain, a food manufacturer uses health and diet consciousness as the segmentation variable.Four segments are developed and coded as follows:
To distinguish between groups, surveys are conducted.On the basis of a questionnaire, people are categorized as belonging to one of these groups.A recent survey asked a random sample of 1,500 Spanish adults (20 and over) to complete the survey.Out of the 1,500 people surveyed, 360 indicated that they are concerned about eating healthy foods.The most recent information available reveals that there are 40,256,000 Spanish adults who are 20 and over.
-{Healthy Foods Narrative} Interpret the confidence interval of p.

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Q 144Q 144

Healthy Foods
In segmenting the frozen meal market in Spain, a food manufacturer uses health and diet consciousness as the segmentation variable.Four segments are developed and coded as follows:
To distinguish between groups, surveys are conducted.On the basis of a questionnaire, people are categorized as belonging to one of these groups.A recent survey asked a random sample of 1,500 Spanish adults (20 and over) to complete the survey.Out of the 1,500 people surveyed, 360 indicated that they are concerned about eating healthy foods.The most recent information available reveals that there are 40,256,000 Spanish adults who are 20 and over.
-{Healthy Foods Narrative} Estimate with 95% confidence thee number of Spanish adults who classify themselves as concerned about eating healthy.

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Q 145Q 145

Tractor Dealership
An accountant was performing an audit for a tractor dealership.An auditor wants to examine the monetary error made by the purchasing order department in the month of July.He decided to randomly sample 100 of the 925 purchase orders for the month of July, and found the amount of error in each one.The statistics for this sample were: = $6.0 and s = $17.012.
-{Tractor Dealership Narrative} Estimate with 95% confidence the average amount of error per purchase order for the entire month of July.

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Q 146Q 146

Tractor Dealership
An accountant was performing an audit for a tractor dealership.An auditor wants to examine the monetary error made by the purchasing order department in the month of July.He decided to randomly sample 100 of the 925 purchase orders for the month of July, and found the amount of error in each one.The statistics for this sample were: = $6.0 and s = $17.012.
-{Tractor Dealership Narrative} Why should the finite population correction factor (FPCF) be used for this problem? Explain.

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Q 147Q 147

Tractor Dealership
An accountant was performing an audit for a tractor dealership.An auditor wants to examine the monetary error made by the purchasing order department in the month of July.He decided to randomly sample 100 of the 925 purchase orders for the month of July, and found the amount of error in each one.The statistics for this sample were: = $6.0 and s = $17.012.
-{Tractor Dealership Narrative} Estimate with 95% confidence the total amount of monetary error for the month of July.

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