# Quiz 7: Hypothesis Testing With Z Tests

Psychology

Q 1Q 1

A single observation can be expressed in a number of ways that all refer to that same observation and the exact same place within the normal curve.These expressions are:
A) formal, informal, and standard.
B) a z score, percentile, and standard score.
C) standard, transformed, and normalized.
D) a raw score, z score, and percentile.

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Multiple Choice

D

Q 2Q 2

To determine a person's percentile, first convert the person's raw score to a:
A) normalized score.
B) z score.
C) median.
D) formal score.

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Multiple Choice

B

Q 3Q 3

To determine a person's percentile, first convert the person's _____ score to a z score.
A) normalized
B) raw
C) median
D) formal

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B

Q 4Q 4

When attempting to find a percentage associated with a z score, the first step involves a _____ to _____ transformation.
A) z score; raw score
B) raw score; z score
C) standard error; z score
D) z score; standard error

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Multiple Choice

Q 5Q 5

When attempting to find a percentage associated with a z score, the second step involves looking up:
A) a raw score on the raw score table.
B) a standard score on the means table.
C) a z score on the z table.
D) the median to determine skewness.

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Multiple Choice

Q 6Q 6

In a raw score to z score transformation, an associated value on the z table provides the percentage of scores:
A) between the mean and the z score.
B) below the mean.
C) above the mean.
D) between the upper and lower limits.

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Multiple Choice

Q 7Q 7

A z score _____ the mean will always be _____.
A) below; positive
B) below; negative
C) above; negative
D) equal to; positive

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Multiple Choice

Q 8Q 8

A z score _____ the mean will always be _____.
A) below; positive
B) above; positive
C) above; negative
D) equal to; positive

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Multiple Choice

Q 9Q 9

A z score _____ the mean will always be _____.
A) below; positive
B) above; negative
C) equal to; negative
D) equal to; zero

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Multiple Choice

Q 10Q 10

The percentile is the:
A) same thing as a percentage.
B) percentage of scores falling at or below a particular raw score.
C) percentage of scores falling at or above a particular raw score.
D) percentage of scores falling between a particular raw score and the mean.

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Multiple Choice

Q 11Q 11

What proportion of a normal distribution corresponds to z scores less than 1.04?
A) 0.3508
B) 0.1492
C) 0.6492
D) 0.8508

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Multiple Choice

Q 12Q 12

In one statistics course, students reported studying an average of 9.92 hours a week, with a standard deviation of 4.54.Treating the class as the population, what is the percentile for a student in the class who studies 11 hours a week? (Round z score to two decimal places.)
A) 9.48
B) 40.52
C) 50.00
D) 59.48

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Multiple Choice

Q 13Q 13

What is the percentage of observations that fall between z scores of -1.02 and 0.61?
A) 22.91
B) 34.61
C) 42.48
D) 57.52

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Multiple Choice

Q 14Q 14

In one statistics course, students reported studying an average of 9.92 hours a week, with a standard deviation of 4.54.Treating this class as the population, what is the percentile for a student in the class who studies 8 hours a week? (Round z score to two decimal places.)
A) 16.28
B) -16.28
C) 33.72
D) -33.72

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Multiple Choice

Q 15Q 15

In one statistics course, students reported studying an average of 9.92 hours a week, with a standard deviation of 4.54.Treating this class as the population, what percent of students study more than 13 hours a week? (Round z score to two decimal places.)
A) 15.91
B) 24.83
C) 25.17
D) 34.09

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Multiple Choice

Q 16Q 16

In one statistics course, students reported studying an average of 9.92 hours a week, with a standard deviation of 4.54.Mark studies 16 hours per week.What percent of students are at least as extreme as Mark, in both directions? (Round z score to two decimal places.)
A) 9.01
B) 10.89
C) 18.02
D) 22.64

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Multiple Choice

Q 17Q 17

In one statistics course, students reported studying an average of 9.92 hours a week, with a standard deviation of 4.54.Jessica is working two jobs and struggles to find time to study, averaging only 3 hours per week.What percent of students are at least as extreme as Jessica, in both directions? (Round z score to two decimal places.)
A) 87.14
B) 43.57
C) 6.43
D) 12.85

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Multiple Choice

Q 18Q 18

If the percentage of scores falling between the mean and a z score of 0.30 is 11.79, then what is the percentage of scores falling between the mean and a z score of -0.30?
A) 11.79
B) -11.79
C) 38.21
D) -38.21

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Multiple Choice

Q 19Q 19

If the percentage of scores falling between the mean and a z score of 0.50 is 19.15, then what is the percentage of scores falling below a z score of -0.50?
A) -19.15
B) 19.15
C) 30.85
D) -30.85

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Multiple Choice

Q 20Q 20

In one statistics course, students reported studying an average of 9.92 hours a week, with a standard deviation of 4.54.Treating this class as the population, what percent of students study more than 8 hours? (Round z score to two decimal places.)
A) 83.35
B) 66.28
C) 56.84
D) 34.72

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Multiple Choice

Q 21Q 21

To convert a person's percentile rank into a raw score, one needs to know the mean and standard:
A) deviation for the population.
B) error of the sampling distribution.
C) deviation of the sample.
D) error of the population.

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Multiple Choice

Q 22Q 22

In one statistics course, students reported studying an average of 9.92 hours a week, with a standard deviation of 4.54.The professor tells Mackenzie she scored at the 46th percentile.How many hours does she study per week? (Round z score to two decimal places.)
A) 0.10 hours
B) 5.53 hours
C) 9.47 hours
D) 10.37 hours

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Multiple Choice

Q 23Q 23

In one statistics course, students reported studying an average of 9.92 hours a week, with a standard deviation of 4.54.The professor tells David he scored at the 76th percentile.How many hours does he study per week? (Round z score to two decimal places.)
A) 13.14 hours
B) 8.64 hours
C) 12.88 hours
D) 16.24 hours

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Multiple Choice

Q 24Q 24

To compare a group mean to a population, compute the:
A) z score.
B) z statistic.
C) mean square error.
D) proportionate reduction in error.

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Multiple Choice

Q 25Q 25

Imagine that the mean height for all Division I women's basketball programs is 69 inches with a standard deviation of 3 inches.The 2010-2011 women's basketball team at the University of Connecticut, with 10 players listed on the roster, had an average height of 71.2 inches.Using the z statistic, what percent of means would fall below that for these UConn Huskies? (Round z score to two decimal places.)
A) 98.98
B) 94.98
C) 86.98
D) 48.98

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Multiple Choice

Q 26Q 26

Assume the average height for American women is 64 inches with a standard deviation of 2 inches.What percent of groups of size 25 would have mean heights of less than 62 inches? (Round z score to two decimal places.)
A) 50.00
B) 0.40
C) 0.13
D) 0

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Multiple Choice

Q 27Q 27

Assume the average height for American women is 64 inches with a standard deviation of 2 inches.What percent of groups of size 25 would have mean heights of more than 64.5 inches? (Round z score to two decimal places.)
A) 10.56
B) 22.82
C) 35.31
D) 89.44

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Multiple Choice

Q 28Q 28

Which statement regarding the denominator of the equation for the z score and that of the z statistic is true?
A) There is no difference between the denominators of the two equations.In both cases, we divide by the standard error.
B) There is no difference between the denominators of the two equations.In both cases, we divide by the standard deviation.
C) When computing a z score, we divide by the population standard deviation, but when computing a z statistic, we divide by the standard error of the sampling distribution.
D) When computing a z statistic, we divide by the population standard deviation, but when computing a z score, we divide by the standard error of the sampling distribution.

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Multiple Choice

Q 29Q 29

The distribution of means has the same mean as the distribution of scores for the population, and the spread is:
A) Tests
B) Nonparameters
C) Parameters
D) Assumptions

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Multiple Choice

Q 30Q 30

Inferential statistical analyses that are NOT based on a set of assumptions about the underlying population are:
A) inaccurate.
B) permissible only when certain assumptions about the sample are met.
C) nonparametric tests.
D) parametric tests.

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Multiple Choice

Q 31Q 31

Under what conditions is the assumption that the dependent variable is assessed on a scale measure NOT met?
A) We are cautious about generalizing the results.
B) The sample size is greater than 30.
C) The data are clearly ratio.
D) The data are clearly nominal or ordinal.

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Multiple Choice

Q 32Q 32

If a dependent variable is nominal, the assumption that the _____ should not be made.
A) variable is normally distributed
B) variable is assessed using a scale measure
C) participants are randomly selected
D) participants are randomly assigned

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Multiple Choice

Q 33Q 33

_____ requires that all members of a population have an equal chance of being selected for a study.
A) Random selection
B) Random assignment
C) Normal distribution
D) Scale variable assumption

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Multiple Choice

Q 34Q 34

Which statement is NOT an assumption of the z test?
A) The distribution of the population is approximately normal.
B) The distribution of the sample is normal.
C) Participants were randomly selected from the population.
D) The dependent variable is assessed using a scale measure.

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Multiple Choice

Q 35Q 35

Which statement is NOT an assumption of parametric hypothesis tests?
A) The population is normally distributed.
B) Participants are selected randomly from the population.
C) The dependent variable is assessed using a scale measure.
D) The sample size is greater than 30.

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Multiple Choice

Q 36Q 36

Under what conditions is it permissible to proceed with a hypothesis test even though the assumption that participants are randomly selected is violated?
A) We are cautious about generalizing the results.
B) The sample size is greater than 30.
C) The data are not clearly ratio.
D) The data are not clearly nominal or ordinal.

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Multiple Choice

Q 37Q 37

Under what conditions is it permissible to proceed with a hypothesis test even though the assumption that the population distribution is approximately normal is violated?
A) We are cautious about generalizing the results.
B) The sample size is greater than 30.
C) The data are not clearly ratio.
D) The data are not clearly nominal or ordinal.

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Multiple Choice

Q 38Q 38

What are the consequences of failing to meet the assumptions of a parametric test when performing research?
A) If we fail to meet the assumptions of a parametric test, then we will be unable to make any inferences regarding the population.
B) If we fail to meet one assumption of a parametric test, then we cannot perform statistical analysis on the results of the study and will be limited to qualitative descriptions of the data.
C) If we fail to meet even one assumption of a parametric test, then we should perform a nonparametric test instead.
D) If the test is robust to the violation, it does not invalidate the research; however, it may make it more difficult to detect effects.

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Multiple Choice

Q 39Q 39

A research study that meets all the assumptions of the parametric test used to analyze the data:
A) continues with the performance of the appropriate nonparametric follow-up test.
B) has no bearing on the results of the research study.
C) produces higher quality results than does a research study that fails to meet some of the assumptions.
D) produces lower quality results than does a research study that fails to meet some of the assumptions.

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Multiple Choice

Q 40Q 40

Because of the principle of _____, when sample sizes are at least 30, the distribution will most likely resemble a normal distribution.
A) parametric statistics
B) nonparametric statistics
C) the central limit theorem
D) robustness

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Multiple Choice

Q 41Q 41

If the assumptions of parametric testing are not met, researchers must:
A) disregard this information and proceed with interpreting results.
B) make a decision to continue with parametric or nonparametric tests.
C) continue with nonparametric tests.
D) get a larger sample size.

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Multiple Choice

Q 42Q 42

A hypothesis test is said to be _____ when it produces fairly accurate results, even when some of the assumptions underlying the hypothesis test are violated.
A) robust
B) invincible
C) reliable
D) fair

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Multiple Choice

Q 43Q 43

Inferential statistical analyses that are based on a set of assumptions about the underlying population are:
A) inaccurate.
B) permissible only when certain assumptions about the sample are met.
C) nonparametric tests.
D) parametric tests.

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Multiple Choice

Q 44Q 44

The research hypothesis states that:
A) the sample being studied is different from the population from which it was drawn.
B) nothing exists.
C) the null hypothesis is not correct.
D) there are no differences between the populations being studied.

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Q 45Q 45

The _____ hypothesis is usually the "exciting" one.
A) null
B) research
C) normalized
D) standard

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Q 46Q 46

The _____ hypothesis is usually the "boring" one.
A) null
B) research
C) normalized
D) standard

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Q 47Q 47

The null hypothesis states that:
A) the sample being studied is different from the population from which it was drawn.
B) nothing exists.
C) a difference exists between the populations being studied.
D) there are no differences between the populations being studied.

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Multiple Choice

Q 48Q 48

The _____ level is the probability used to determine the critical values, or cutoffs, in hypothesis testing.
A) z
B) M
C) p
D) s

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Multiple Choice

Q 49Q 49

When calculating a z test, one compares data from the sample to a:
A) sample distribution.
B) population distribution.
C) distribution determined by the null hypothesis.
D) distribution determined by the research hypothesis.

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Multiple Choice

Q 50Q 50

The typical probability adopted by researchers to determine whether a result is extreme is:
A) 0.01.
B) 0.05.
C) 0.25.
D) 0.50.

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Multiple Choice

Q 51Q 51

One rejects the null hypothesis when the test statistic falls in which area of the distribution?
A) critical value
B) critical region
C) region of determination
D) probability region

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Multiple Choice

Q 52Q 52

One rejects the null hypothesis only when:
A) the sample mean is larger than the population mean.
B) the p value associated with the test statistic is smaller than the p level chosen.
C) the sample mean is smaller than the population mean.
D) the p value associated with the test statistic is greater than the p level chosen.

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Multiple Choice

Q 53Q 53

The statistical concept of p levels is often referred to as:
A) betas.
B) alphas.
C) central tendency.
D) variability.

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Multiple Choice

Q 54Q 54

The area in the tails of the comparison distribution in which the null hypothesis can be rejected is called the _____.
A) critical value
B) cutoff
C) p level
D) critical region

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Q 55Q 55

If one rejects the null hypothesis, the result is said to be:
A) acceptable.
B) important.
C) statistically significant.
D) valid.

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Q 56Q 56

The phrase statistically significant means that the:
A) research finding is not important.
B) research finding is of practical importance.
C) research result was unlikely to have occurred by chance.
D) research finding is of theoretical importance.

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Multiple Choice

Q 57Q 57

If one fails to reject the null hypothesis, the result is said to be:
A) unacceptable.
B) unimportant.
C) not statistically significant.
D) valid.

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Multiple Choice

Q 58Q 58

Use the following to answer questions
Study Description: Tail Wagging
A New York Times article published on April 24, 2007, reported the research of Dr.Giorgio Vallortigara, a neuroscientist at the University of Trieste, Italy, and his two colleagues.The researchers asked whether a dog wags its tail in a preferred direction in response to positive stimuli and in another direction in response to negative stimuli.To answer their question, they recruited 30 dogs that were family pets.Filming each dog from above, they allowed it to view (through a slat in its cage) three positive stimuli separately, in order of descending positivity: its owner, an unfamiliar human, and a cat.All the dogs responded by wagging their tails to the right.But when the dogs were presented with an unfamiliar, aggressive dog, a negative stimulus, all dogs wagged their tails to the left.
-(Study Description: Tail Wagging) Which statement is the null hypothesis for this study?
A) A dog will wag its tail more to the left in response to positive stimuli and more to the right in response to negative stimuli.
B) A dog's tail wagging will be the same in response to positive stimuli as to negative stimuli.
C) A dog will wag its tail differently in response to positive stimuli than to negative stimuli.
D) A dog's tail will wag more to the right in response to positive stimuli and more to the left in response to negative stimuli.

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Multiple Choice

Q 59Q 59

Use the following to answer questions
Study Description: Tail Wagging
A New York Times article published on April 24, 2007, reported the research of Dr.Giorgio Vallortigara, a neuroscientist at the University of Trieste, Italy, and his two colleagues.The researchers asked whether a dog wags its tail in a preferred direction in response to positive stimuli and in another direction in response to negative stimuli.To answer their question, they recruited 30 dogs that were family pets.Filming each dog from above, they allowed it to view (through a slat in its cage) three positive stimuli separately, in order of descending positivity: its owner, an unfamiliar human, and a cat.All the dogs responded by wagging their tails to the right.But when the dogs were presented with an unfamiliar, aggressive dog, a negative stimulus, all dogs wagged their tails to the left.
-(Study Description: Tail Wagging) Which statement is the research hypothesis for this study?
A) A dog's tail will wag more to the left in response to positive stimuli and more to the right in response to negative stimuli.
B) There will be no difference in a dog's tail wagging while viewing positive and negative stimuli.
C) A dog's tail will wag differently in response to positive stimuli than to negative stimuli.
D) A dog's tail will wag more to the right in response to positive stimuli and more to the left in response to negative stimuli.

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Multiple Choice

Q 60Q 60

Use the following to answer questions
Study Description: Dance Dance Revolution
Unnithan, Houser, and Fernhall (2006) were interested in whether playing the game Dance Dance Revolution (DDR) affected the heart rate of overweight adolescents differently than it affected non-overweight adolescents.Twenty-two adolescents, 10 classified as overweight and 12 as not overweight, played DDR for 12 minutes, while the researchers measured each participant's heart rate.On average, the researchers found no difference between the heart rate of the two groups.
-(Study Description: Dance Dance Revolution) Which statement is the null hypothesis for this study?
A) There will be no difference in the heart rate of the two groups after playing Dance Dance Revolution.
B) The heart rate of the overweight group will be faster than that of the non-overweight group after both groups play Dance Dance Revolution.
C) The heart rate of the non-overweight group will be faster than that of the overweight group after both groups play Dance Dance Revolution.
D) The heart rates of the overweight group and the non-overweight group will differ after both groups play Dance Dance Revolution.

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Multiple Choice

Q 61Q 61

Use the following to answer questions
Study Description: Dance Dance Revolution
Unnithan, Houser, and Fernhall (2006) were interested in whether playing the game Dance Dance Revolution (DDR) affected the heart rate of overweight adolescents differently than it affected non-overweight adolescents.Twenty-two adolescents, 10 classified as overweight and 12 as not overweight, played DDR for 12 minutes, while the researchers measured each participant's heart rate.On average, the researchers found no difference between the heart rate of the two groups.
-(Study Description: Dance Dance Revolution) Which statement is the research hypothesis for this study?
A) There will be no difference in the heart rates of the two groups after both groups play Dance Dance Revolution.
B) The heart rate of the overweight group will be faster than that of the non-overweight group after both groups play Dance Dance Revolution.
C) The heart rate of the non-overweight group will be faster that of the overweight group after both groups play Dance Dance Revolution.
D) The heart rates of the overweight group and the non-overweight group will differ after both groups play Dance Dance Revolution.

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Multiple Choice

Q 62Q 62

Rose believes there is a positive correlation between watching violence on television and aggressive behavior.What would be her null hypothesis?
A) Watching violent TV shows increases aggressive behavior.
B) Watching violent TV shows is not related to level of aggressive behavior.
C) Watching violent TV shows causes aggressive behavior.
D) Only aggressive people watch violent TV shows.

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Multiple Choice

Q 63Q 63

The symbol for the null hypothesis is _____ and the symbol for the research hypothesis is _____.
A) H

_{1}; H_{0}B) H_{0}; H_{1}C) ; M D) _{0}; _{1}Free

Multiple Choice

Q 64Q 64

Mehl (2007) published a study in the journal Science reporting the results of an extensive study of 396 men and women comparing the number of words uttered per day by each sex.If Mehl was testing the idea that women talk more than men, what type of hypothesis test would he conduct?
A) one-tailed test
B) two-tailed test
C) nonparametric test
D) z test

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Multiple Choice

Q 65Q 65

The statement "It is hypothesized that children who participate in a mentoring program will score lower on depression tests compared to children who do not participate in a mentoring program" best illustrates a:
A) one-tailed test.
B) two-tailed test.
C) null hypothesis.
D) z test.

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Multiple Choice

Q 66Q 66

When hypothesis testing, a more common approach is to use a _____ rather than a _____.
A) two-tailed test; one-tailed test
B) one-tailed test; two-tailed test
C) null hypothesis; research hypothesis
D) research hypothesis; null hypothesis

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Multiple Choice

Q 67Q 67

The statement "It is hypothesized that men and women will differ on reaction time measures" best illustrates a:
A) one-tailed test.
B) two-tailed test.
C) null hypothesis.
D) z test.

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Multiple Choice

Q 68Q 68

The statement, "It is hypothesized that participants in a stress condition will perform in a significantly different manner than participants in a control group on a series of memory tasks" best illustrates a:
A) one-tailed test.
B) two-tailed test.
C) null hypothesis.
D) z test.

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Multiple Choice

Q 69Q 69

The critical value(s) associated with a p level of 0.05 for a two-tailed hypothesis test using the z statistic is (are):
A) 1.96.
B) 1.65.
C) -1.65 and 1.65.
D) -1.96 and 1.96.

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Multiple Choice

Q 70Q 70

The critical value(s) associated with a p level of 0.05 for a one-tailed hypothesis test using the z statistic is (are):
A) 1.96.
B) 1.65.
C) -1.65 or 1.65.
D) -1.96 and 1.96.

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Multiple Choice

Q 71Q 71

The behavioral sciences typically use alpha of 0.05.How do they represent this value and what does it mean?
A) A p value, which means scores in the most extreme 2.5 percent on either end of the distribution, will be evidence to reject the null hypothesis.
B) A p value, which means scores 5 percent on either side of the mean, will be evidence to reject the null hypothesis.
C) A z statistic, which means scores in the most extreme 2.5 percent on either end of the distribution, will be evidence to reject the null hypothesis.
D) A z statistic, which means scores 5 percent on either side of the mean, will be evidence to reject the null hypothesis.

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Multiple Choice

Q 72Q 72

Claire knows the z score for her research hypothesis is -2.05, and her critical values are -1.96 and 1.96 for a p value of 0.05.What should she conclude about her hypothesis given these statistics?
A) She should reject the null hypothesis and report the direction of the effect because the score is in a critical region (below -1.96).
B) She should reject the null hypothesis but not report the direction of the effect because she doesn't have enough information.
C) She should fail to reject the null hypothesis because the score is not in a critical region (above 1.96 or below -1.96).
D) She should fail to reject the null hypothesis because she doesn't have enough information.

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Multiple Choice

Q 73Q 73

A major reason replication of scientific findings has rarely been attempted is because:
A) there is pressure to not question other researchers' findings.
B) journals tend to publish only new research.
C) of lack of interest in other researchers' work.
D) the media uses these results to criticize previous research.

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Q 74Q 74

Replication involves conducting:
A) the same study with similar samples and getting the same results each time.
B) the same study with different samples and getting the same results each time.
C) the same study with the same sample and getting the same results each time.
D) two different studies with the same sample and getting the same results each time.

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Multiple Choice

Q 75Q 75

If we conduct the same study with different samples and get the same results each time, it is:
A) more likely we have an error in our results.
B) more likely the results are accurate.
C) less likely the results are accurate.
D) less likely we can reject the null hypothesis.

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Multiple Choice

Q 76Q 76

When multiple researchers recruit participants from various locations to replicate findings it is called:
A) crowd-sourcing science.
B) stealing other researchers' work.
C) independent science.
D) new research.

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Q 77Q 77

The crowd-sourcing movement in research is:
A) closed science.
B) new science.
C) open science.
D) dirty science.

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Q 78Q 78

If studies fail to replicate:
A) it is unlikely the original study is accurate.
B) science is a failure itself.
C) it can help us better understand the context under which findings might exist.
D) it confuses our understanding of the original study.

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True False

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Q 82Q 82

If 28 percent of scores fall between a negative z score and the mean, then 32 percent of scores fall below that z score.

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True False

Q 83Q 83

If 28 percent of scores fall between a negative z score and the mean, then 22 percent of scores fall below that z score.

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True False

Q 84Q 84

When determining the z value for a mean rather than a score, the value is called a standardized z.

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True False

Q 85Q 85

The same logic used to find an individual's percentile rank can be applied to a mean to determine the relative standing of the mean in a distribution of means.

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True False

Q 86Q 86

For a given population with a mean of 100 and a standard deviation of 20, a score of less than 80 is less likely to occur than a score of 80 based on 25 observations.

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True False

Q 87Q 87

When determining the z value for a mean rather than a score, the value is called a z statistic.

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True False

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Q 90Q 90

Most hypothesis tests are robust to violations of the assumption that the distribution of the population is approximately normal.

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True False

Q 91Q 91

As long as the sample size is greater than 30, the results of a study can be generalized to most populations.

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True False

Q 92Q 92

As long as the sample size is greater than 30, one can assume that the underlying population has an approximately normal distribution.

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True False

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Q 95Q 95

The critical values for a statistical test mark the value beyond which one can fail to reject the null hypothesis.

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Q 96Q 96

The critical values for a statistical test mark the value beyond which one can reject the null hypothesis.

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True False

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Q 98Q 98

If one fails to reject the null hypothesis, it means that the results of the study are not statistically significant.

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True False

Q 99Q 99

If a result is statistically significant, then chance is said NOT to account for the outcome.

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True False

Q 100Q 100

If one fails to reject the null hypothesis, it means that the results of the study are statistically significant.

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Q 105Q 105

A z test result of 1.98 would allow one to reject the null hypothesis, assuming a two-tailed test with p = 0.05.

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True False

Q 106Q 106

A z test result of -1.94 would allow one to reject the null hypothesis, assuming a two-tailed test with p = 0.05.

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Q 112Q 112

Which of these is NOT an appropriate tool for locating a specific point on a normal bell-shaped curve?
A) raw scores
B) sum of squares
C) z scores
D) percentile rankings

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Multiple Choice

Q 113Q 113

The average do-it-yourself bedroom makeover costs $475 with a standard deviation of $86 (fictional data).Tanya redoes her daughter's room for $654.What percent of bedroom makeovers cost less than Tanya spent? (Round z score to two decimal places.)
A) 1.88%
B) 38.49%
C) 48.12%
D) 98.12%

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Multiple Choice

Q 114Q 114

India converts her raw score on a memory scale to a z score and finds that her score corresponds to a z score of -0.92.She knows her score is below the mean.What percent of people scored lower than India on the memory scale?
A) 17.88%
B) 31.12%
C) 50.00%
D) 81.12%

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Multiple Choice

Q 115Q 115

Stephanie wonders whether college textbooks change in price as students advance in their academic work.She finds some national data on college textbooks that indicates the average price of a text is $96 with a standard deviation of $31.She decides to collect the prices of 30 textbooks that are required for senior-level courses at her university.She finds the average cost to be $89.What is the percentile rank of Stephanie's collection of books? (Round z score to two decimal places.)
A) 8.71
B) 10.75
C) 39.25
D) 41.29

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Multiple Choice

Q 116Q 116

A given distribution has a mean of 50 and a standard deviation of 5.When comparing a score of 55 to this distribution of scores, the percentile rank is _____, whereas comparing a mean of 55, based on a sample of 10, to a distribution of means created from this parent population will result in a percentile rank of _____.
A) 1.00; 1.00
B) 1.00; 3.16
C) 3.16; 1.00
D) 50.50; 55.10

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Multiple Choice

Q 117Q 117

Philip is going to proceed with data analysis on a sample of scores that violate many assumptions about the population of interest.Which test would be more appropriate to use?
A) parametric
B) nonparametric
C) skewed
D) biased

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Multiple Choice

Q 118Q 118

A _____ test makes assumptions about the population, whereas a _____test does not.
A) nonparametric; parametric
B) parametric; nonparametric
C) linear; nonlinear
D) nonlinear; linear

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Multiple Choice

Q 119Q 119

Why is it important to check for violations of assumptions when hypothesis testing?
A) It is a step in graphing the data, which is required for publishing scientific results.
B) Specific assumptions must be violated before we can make inferences from our study sample to the overall population.
C) Results from data analyses are valid only when assumptions have been violated.
D) We are making inferences about the population of interest that will be maximally valid if specific requirements are met.

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Multiple Choice

Q 120Q 120

A test is said to be _____ when it produces fairly accurate results even when the data suggest that the population might not meet some of the assumptions.
A) parametric
B) nonparametric
C) nonlinear
D) robust

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Multiple Choice

Q 121Q 121

In the six steps of hypothesis testing, when are the null and research hypothesis stated in relation to calculating the test statistic?
A) The hypothesis is stated before calculating the test statistic because it is the predicted outcome for the question of interest and would not be informative or fairly conceived after the data are analyzed.
B) The hypothesis is formulated at the end of the process, after calculating the test statistic and a conclusion is reached.
C) The hypothesis is the actual outcome of the study and cannot be verified unless it is formulated after the test statistic.
D) The hypothesis changes throughout the process in response to any new information found during testing.

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Multiple Choice

Q 122Q 122

Melanie, a school psychologist, wants to compare the test scores of students in her school to the national average.Which is the appropriate order of some of the steps she should follow?
A) state the hypotheses; determine the characteristics of the comparison distribution; identify populations, distribution, and assumptions; calculate the test statistic; reject or fail to reject the null hypothesis
B) identify populations, distribution, and assumptions; determine the characteristics of the comparison distribution; calculate the test statistic; state the hypotheses; reject or fail to reject the null hypothesis
C) identify populations, distribution, and assumptions; state the hypotheses; determine the characteristics of the comparison distribution; calculate the test statistic; reject or fail to reject the null hypothesis
D) identify populations, distribution, and assumptions; state the hypotheses; reject or fail to reject the null hypothesis; determine the characteristics of the comparison distribution; calculate the test statistic

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Multiple Choice

Q 123Q 123

In hypothesis testing, critical values are:
A) the minimum and maximum scores.
B) the spread of the comparison distribution.
C) the test statistic value beyond which we reject the null hypothesis.
D) the levels of the independent variable.

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Multiple Choice

Q 124Q 124

The statement "It is hypothesized that students will score higher on their test when they eat breakfast beforehand compared to not eating breakfast." best illustrates an example of a:
A) one-tailed test.
B) two-tailed test.
C) parametric test.
D) nonparametric test.

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Multiple Choice

Q 125Q 125

Jin predicts that people with highly symmetric faces will be rated as more attractive than people with less symmetric facial features.Is this hypothesis one- or two-tailed?
A) two-tailed, because it is directional
B) two-tailed, because it indicates there will be a difference and the direction
C) one-tailed, because it only indicates there will be a difference but not the direction
D) one-tailed, because it is directional

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Multiple Choice

Q 126Q 126

If a researcher wanted to determine whether her results were specific to the sample or context used, she should:
A) rerun her analyses to make sure they are accurate.
B) replicate the study with different people.
C) replicate the study with the same people.
D) throw the data away and start over again from scratch to see if she gets the same results.

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Multiple Choice

Q 127Q 127

Demi converted scores from a customer service questionnaire to z scores, and some of them are negative.She is trying to use a z table but is confused because there are no negative z scores in the tables.What should she do?
A) Use the positive value because the normal curve is symmetric.
B) Square the negative z-score value so that it becomes positive.
C) Add 1.0 to the negative z-score value so that it becomes positive.
D) Use 0 as the value for the z score.

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Multiple Choice

Q 128Q 128

Atif has a z score of 0.98 from a converted IQ score.From a z table, the percentage between his score and the mean is 33.65 percent.What percent of people have IQs at or lower than Atif's score?
A) 33.65
B) 50.00
C) 67.30
D) 83.65

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Multiple Choice

Q 129Q 129

Children are regularly assessed for their height and weight compared to national data provided by the Centers for Disease Control.Dahlin is somewhat short for his age, and his mother notices on his medical chart that it says Height: z = -1.67.What does this tell Dahlin's mother about his height?
A) 4.75 percent of children are shorter than Dahlin.
B) 45.25 percent of children are shorter than Dahlin.
C) 4.75 percent of children are taller than Dahlin.
D) 45.25 percent of children are taller than Dahlin.

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Multiple Choice

Q 130Q 130

In January 2011, the United States saw an increase in gas prices.Imagine the average price per gallon was $3.12 with a standard deviation of $0.27, according to a source such as AAA (Automobile Association of America) that tracks gas prices.Adam is on his long mid-semester break, so he and some of his friends decide to go on a 3000-mile road trip.He records the price of gas each of the 10 times they fill up the tank, and he computes an average price per gallon of $3.16.What percent of other sample means, based on 10 gas stations, would be greater than the one Adam observed? (Round z score to two decimal places.)
A) 19.85
B) 31.92
C) 69.85
D) 80.15

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Multiple Choice

Q 131Q 131

Which statement is NOT a general assumption of hypothesis testing specifically for the z test?
A) The dependent variable is assessed using a scale measure.
B) The participants are randomly selected.
C) The distribution of the underlying population is bimodal.
D) The distribution of the underlying population is approximately normal.

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Multiple Choice

Q 132Q 132

Under what conditions are the inferential statistics used typically robust against violations of assumptions?
A) only if the independent variable is not clearly nominal or ordinal
B) only if the participants were not randomly selected but we are cautious when generalizing
C) only if the population is not normally distributed but there are at least 30 data points in the sample
D) only if the independent variable is not clearly nominal or ordinal, participants were not randomly selected but we are cautious when generalizing, and the population is not normally distributed but there are at least 30 data points in the sample

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Multiple Choice

Q 133Q 133

The first step in hypothesis testing is:
A) stating the null and research hypotheses.
B) determining the characteristics of the comparison distribution.
C) selecting the appropriate test based on the population, comparison distribution, and underlying assumptions.
D) determining the critical values for a test.

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Multiple Choice

Q 134Q 134

The _____ refers to the areas in the tails of the distribution in which one determines statistical significance or rejection of the null hypothesis.
A) critical value
B) standard error
C) critical region
D) hypothesis

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Multiple Choice

Q 135Q 135

The _____ is a test statistic value beyond which one rejects the null hypothesis.
A) critical value
B) standard error
C) critical region
D) hypothesis

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Multiple Choice

Q 136Q 136

The second step in hypothesis testing is:
A) stating the null and research hypotheses.
B) determining the characteristics of the comparison distribution.
C) selecting the appropriate test based on the population, comparison distribution, and underlying assumptions.
D) determining the critical values for a test.

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Multiple Choice

Q 137Q 137

The third step in hypothesis testing is:
A) stating the null and research hypotheses.
B) determining the characteristics of the comparison distribution.
C) selecting the appropriate test based on the population, comparison distribution, and underlying assumptions.
D) determining the critical values for a test.

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Multiple Choice

Q 138Q 138

The fourth step in hypothesis testing is:
A) stating the null and research hypotheses.
B) determining the characteristics of the comparison distribution.
C) selecting the appropriate test based on the population, comparison distribution, and underlying assumptions.
D) determining the critical values for a test.

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Multiple Choice

Q 139Q 139

The fifth step in hypothesis testing is:
A) calculating the test statistic
B) determining the characteristics of the comparison distribution.
C) selecting the appropriate test based on the population, comparison distribution, and underlying assumptions.
D) making a decision.

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Multiple Choice

Q 140Q 140

The sixth step in hypothesis testing is:
A) calculating the test statistic
B) determining the characteristics of the comparison distribution.
C) selecting the appropriate test based on the population, comparison distribution, and underlying assumptions.
D) making a decision.

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Multiple Choice

Q 141Q 141

When p < 0.05, the findings could be:
A) statistically significant.
B) practically important.
C) clinically significant.
D) false.

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Multiple Choice