Question 1

Poker Time: The amount of time spent by American adults playing Poker per week is normally distributed with a mean of 4 hours and standard deviation of 1.25 hours.
-Find the probability that a randomly selected American adult plays Poker for more than 5 hours per week.

Accepted Answer

The answer of Poker Time: The amount of time spent...

Question 2

Barack Obama
Bill Clinton, the former President of the United States, believes that the proportion of voters who will vote for Barack Obama in the year 2012 presidential elections is 0.65. A sample of 500 voters is selected at random.
-{Barack Obama Narrative} What is the probability that the number of voters in the sample who will vote for Barack Obama in the year 2012 is between 340 and 350?

Accepted Answer

The answer of Barack Obama
Bill Clinton, the former President of...

Question 3

A CPA knows from past history that the average accounts receivable for a company is $521.72 with a standard deviation of $584.64. If the auditor takes a simple random sample of 100 accounts, what is the probability that the mean of the sample is within $120 of the population mean?

Accepted Answer

The answer of A CPA knows from past history that...

Question 4

What is the probability that the sample mean is between 2,000 and 2,300 magazines?

Accepted Answer

The answer of What is the probability that the sample...

Question 5

Suppose it is known that 60% of radio listeners at a particular college are smokers. A sample of 500 students from the college is selected at random. Approximate the probability that at least 280 of these students are radio listeners.

Accepted Answer

The answer of Suppose it is known that 60% of...

Question 6

Number of Fish Tanks: The following data give the number of fish tanks owned for a population of 4 families.
 
-A sample of size 2 is drawn at random from the population. Use the formulas  and  to calculate the mean and the standard deviation of the sampling distribution of the sample means.

Accepted Answer

The answer of Number of Fish Tanks: The following data...

Question 7

Barack Obama
Bill Clinton, the former President of the United States, believes that the proportion of voters who will vote for Barack Obama in the year 2012 presidential elections is 0.65. A sample of 500 voters is selected at random.
-{Barack Obama Narrative} Find the expected value and the standard deviation of the sample proportion  .

Accepted Answer

The answer of Barack Obama
Bill Clinton, the former President of...

Question 8

Heights of Men
The heights of men in the USA are normally distributed with a mean of 68 inches and a standard deviation of 4 inches.
-{Heights of Men Narrative} If the population of men's heights is not normally distributed, which, if any, of the previous questions can you answer?

Accepted Answer

The answer of Heights of Men
The heights of men in...

Question 9

Number of Fish Tanks: The following data give the number of fish tanks owned for a population of 4 families.
 
-List all possible samples of 2 families that can be selected without replacement from this population, and compute the sample mean  for each sample.

Accepted Answer

The answer of Number of Fish Tanks: The following data...

Question 10

What is the shape of the sampling distribution of the sample mean number of magazines sold per day? Why?

Accepted Answer

The answer of What is the shape of the sampling...

Question 11

Number of Fish Tanks: The following data give the number of fish tanks owned for a population of 4 families.
 
-Find the sampling distribution of  , and use it to calculate the mean and the standard deviation of  .

Accepted Answer

The answer of Number of Fish Tanks: The following data...

Question 12

Poker Time: The amount of time spent by American adults playing Poker per week is normally distributed with a mean of 4 hours and standard deviation of 1.25 hours.
-Find the probability that if four American adults are randomly selected, their average number of hours spent playing Poker is more than 5 hours per week.

Accepted Answer

The answer of Poker Time: The amount of time spent...

Question 13

Number of Fish Tanks: The following data give the number of fish tanks owned for a population of 4 families.
 
-Find the mean and the standard deviation for the population.

Accepted Answer

The answer of Number of Fish Tanks: The following data...

Question 14

Find the expected value and the standard error of the sample mean.

Accepted Answer

The answer of Find the expected value and the standard...

Question 15

Heights of Men
The heights of men in the USA are normally distributed with a mean of 68 inches and a standard deviation of 4 inches.
-{Heights of Men Narrative} A random sample of five men is selected. What is the probability that the sample mean is greater than 70 inches?

Accepted Answer

The answer of Heights of Men
The heights of men in...

Question 16

Heights of Men
The heights of men in the USA are normally distributed with a mean of 68 inches and a standard deviation of 4 inches.
-{Heights of Men Narrative} What is the probability that the mean height of a random sample of 36 men is greater than 70 inches?

Accepted Answer

The answer of Heights of Men
The heights of men in...

Question 17

In a given year, the average annual salary of a NHL hockey player was $205,000 with a standard deviation of $24,500. If a simple random sample of 50 players was taken, what is the probability that the sample mean will exceed $210,000?

Accepted Answer

The answer of In a given year, the average annual...

Question 18

Barack Obama
Bill Clinton, the former President of the United States, believes that the proportion of voters who will vote for Barack Obama in the year 2012 presidential elections is 0.65. A sample of 500 voters is selected at random.
-{Barack Obama Narrative} Assume that Gore is correct and p = 0.65. What is the sampling distribution of the sample proportion  ? Explain.

Accepted Answer

The answer of Barack Obama
Bill Clinton, the former President of...

Question 19

What is the probability that you get more than 200 heads if you flip a coin 400 times?

Accepted Answer

The answer of What is the probability that you get...

Question 20

Heights of Men
The heights of men in the USA are normally distributed with a mean of 68 inches and a standard deviation of 4 inches.
-{Heights of Men Narrative} What is the probability that a randomly selected man is taller than 70 inches?

Accepted Answer

The answer of Heights of Men
The heights of men in...

Quiz 8: Sampling Distributions

Poker Time: The amount of time spent by American adults playing Poker per week is normally distributed with a mean of 4 hours and standard deviation of 1.25 hours. -Find the probability that a randomly selected American adult plays Poker for more than 5 hours per week.

A CPA knows from past history that the average accounts receivable for a company is $521.72 with a standard deviation of $584.64. If the auditor takes a simple random sample of 100 accounts, what is the probability that the mean of the sample is within $120 of the population mean?

What is the probability that the sample mean is between 2,000 and 2,300 magazines?

Suppose it is known that 60% of radio listeners at a particular college are smokers. A sample of 500 students from the college is selected at random. Approximate the probability that at least 280 of these students are radio listeners.

Number of Fish Tanks: The following data give the number of fish tanks owned for a population of 4 families. -A sample of size 2 is drawn at random from the population. Use the formulas and to calculate the mean and the standard deviation of the sampling distribution of the sample means.

Heights of Men The heights of men in the USA are normally distributed with a mean of 68 inches and a standard deviation of 4 inches. -{Heights of Men Narrative} If the population of men's heights is not normally distributed, which, if any, of the previous questions can you answer?

Number of Fish Tanks: The following data give the number of fish tanks owned for a population of 4 families. -List all possible samples of 2 families that can be selected without replacement from this population, and compute the sample mean for each sample.

What is the shape of the sampling distribution of the sample mean number of magazines sold per day? Why?

Number of Fish Tanks: The following data give the number of fish tanks owned for a population of 4 families. -Find the sampling distribution of , and use it to calculate the mean and the standard deviation of .

Number of Fish Tanks: The following data give the number of fish tanks owned for a population of 4 families. -Find the mean and the standard deviation for the population.

Find the expected value and the standard error of the sample mean.

Heights of Men The heights of men in the USA are normally distributed with a mean of 68 inches and a standard deviation of 4 inches. -{Heights of Men Narrative} A random sample of five men is selected. What is the probability that the sample mean is greater than 70 inches?

Heights of Men The heights of men in the USA are normally distributed with a mean of 68 inches and a standard deviation of 4 inches. -{Heights of Men Narrative} What is the probability that the mean height of a random sample of 36 men is greater than 70 inches?

In a given year, the average annual salary of a NHL hockey player was $205,000 with a standard deviation of $24,500. If a simple random sample of 50 players was taken, what is the probability that the sample mean will exceed $210,000?

What is the probability that you get more than 200 heads if you flip a coin 400 times?

Heights of Men The heights of men in the USA are normally distributed with a mean of 68 inches and a standard deviation of 4 inches. -{Heights of Men Narrative} What is the probability that a randomly selected man is taller than 70 inches?