Question 1

Average Annual Revenue
 Suppose that the average annual revenue of a small business is $150,000 with a standard deviation of $40,000.Assume that the revenue distribution is normal. ​ ​
-{Average Annual Revenue Narrative} What is the probability that one business selected at random makes less than $120,000?

Accepted Answer

The answer of  Average Annual Revenue
 Suppose that the...

Question 2

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...

Question 3

Retirees
 A sample of 50 retirees is drawn at random from a normal population whose mean age and standard deviation are 75 and 6 years,respectively. ​ ​
-{Retirees Narrative} What is the probability that the mean age exceeds 73 years?

Accepted Answer

The answer of Retirees
 A sample of 50 retirees is...

Question 4

Mean Salary
 In order to estimate the mean salary for a population of 500 employees,the president of a certain company selected at random a sample of 40 employees. ​ ​
-{Mean Salary Narrative} If the population standard deviation is $800,compute the standard error both with and without using the finite population correction factor.

Accepted Answer

The answer of  Mean Salary
 In order to estimate...

Question 5

Average Annual Revenue
 Suppose that the average annual revenue of a small business is $150,000 with a standard deviation of $40,000.Assume that the revenue distribution is normal. ​ ​
-{Average Annual Revenue Narrative} Could you have used a normal distribution to find an (approximate)probability for the average of 4 revenues if the population of revenues did not have a normal distribution?

Accepted Answer

The answer of  Average Annual Revenue
 Suppose that the...

Question 6

Average Annual Revenue
 Suppose that the average annual revenue of a small business is $150,000 with a standard deviation of $40,000.Assume that the revenue distribution is normal. ​ ​
-{Average Annual Revenue Narrative} What is the probability that the average annual revenue of a random sample of 4 businesses is less than $120,000?

Accepted Answer

The answer of  Average Annual Revenue
 Suppose that the...

Question 7

Average Annual Revenue
 Suppose that the average annual revenue of a small business is $150,000 with a standard deviation of $40,000.Assume that the revenue distribution is normal. ​ ​
-{Average Annual Revenue Narrative} Why are your answers to the previous two questions different?

Accepted Answer

The answer of  Average Annual Revenue
 Suppose that the...

Question 8

Retirees
 A sample of 50 retirees is drawn at random from a normal population whose mean age and standard deviation are 75 and 6 years,respectively. ​ ​
-{Retirees Narrative} What is the probability that two randomly selected retirees are over 73 years of age?

Accepted Answer

The answer of Retirees
 A sample of 50 retirees is...

Question 9

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...

Question 10

Retirees
 A sample of 50 retirees is drawn at random from a normal population whose mean age and standard deviation are 75 and 6 years,respectively. ​ ​
-{Retirees Narrative} What is the probability that the mean age is at most 73 years?

Accepted Answer

The answer of Retirees
 A sample of 50 retirees is...

Question 11

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...

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. ​ ​
-{Poker Time Narrative} 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 13

Mean Salary
 In order to estimate the mean salary for a population of 500 employees,the president of a certain company selected at random a sample of 40 employees. ​ ​
-{Mean Salary Narrative} Would you use the finite population correction factor in calculating the standard error of the sample mean in this case? Explain.

Accepted Answer

The answer of  Mean Salary
 In order to estimate...

Question 14

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. ​ ​
-{Poker Time Narrative} Find the probability that if four American adults are randomly selected,all four play Poker for more than 5 hours per week.

Accepted Answer

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

Question 15

Heights of Fences 
Heights of fences are normally distributed with a mean of 52 inches and a standard deviation of 4 inches. ​ ​
-{Heights of Fence Narrative} Find the probability that two randomly selected fences are both under 54 inches.

Accepted Answer

The answer of Heights of Fences 
Heights of fences are...

Question 16

Retirees
 A sample of 50 retirees is drawn at random from a normal population whose mean age and standard deviation are 75 and 6 years,respectively. ​ ​
-(Retirees Narrative} Find the mean and standard error of the sampling distribution of the sample mean.

Accepted Answer

The answer of Retirees
 A sample of 50 retirees is...

Question 17

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. ​ ​
-{Poker Time Narrative} 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 18

Retirees
 A sample of 50 retirees is drawn at random from a normal population whose mean age and standard deviation are 75 and 6 years,respectively. ​ ​
-(Retirees Narrative} Describe the shape of the sampling distribution of the sample mean in this case.

Accepted Answer

The answer of Retirees
 A sample of 50 retirees is...

Question 19

Heights of Fences 
Heights of fences are normally distributed with a mean of 52 inches and a standard deviation of 4 inches. ​ ​
-{Heights of Fence Narrative} Find the probability that the mean height of 4 randomly selected fences is under 54 inches.

Accepted Answer

The answer of Heights of Fences 
Heights of fences are...

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} 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...

Quiz 9: Sampling Distributions

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?

Retirees A sample of 50 retirees is drawn at random from a normal population whose mean age and standard deviation are 75 and 6 years,respectively. -{Retirees Narrative} What is the probability that the mean age exceeds 73 years?

Average Annual Revenue Suppose that the average annual revenue of a small business is $150,000 with a standard deviation of $40,000.Assume that the revenue distribution is normal. -{Average Annual Revenue Narrative} Why are your answers to the previous two questions different?

Retirees A sample of 50 retirees is drawn at random from a normal population whose mean age and standard deviation are 75 and 6 years,respectively. -{Retirees Narrative} What is the probability that two randomly selected retirees are over 73 years of age?

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?

Retirees A sample of 50 retirees is drawn at random from a normal population whose mean age and standard deviation are 75 and 6 years,respectively. -{Retirees Narrative} What is the probability that the mean age is at most 73 years?

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?

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. -{Poker Time Narrative} Find the probability that a randomly selected American adult plays Poker for more than 5 hours per week.

Heights of Fences Heights of fences are normally distributed with a mean of 52 inches and a standard deviation of 4 inches. -{Heights of Fence Narrative} Find the probability that two randomly selected fences are both under 54 inches.

Retirees A sample of 50 retirees is drawn at random from a normal population whose mean age and standard deviation are 75 and 6 years,respectively. -(Retirees Narrative} Find the mean and standard error of the sampling distribution of the sample mean.

Retirees A sample of 50 retirees is drawn at random from a normal population whose mean age and standard deviation are 75 and 6 years,respectively. -(Retirees Narrative} Describe the shape of the sampling distribution of the sample mean in this case.

Heights of Fences Heights of fences are normally distributed with a mean of 52 inches and a standard deviation of 4 inches. -{Heights of Fence Narrative} Find the probability that the mean height of 4 randomly selected fences is under 54 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} A random sample of five men is selected.What is the probability that the sample mean is greater than 70 inches?

Quiz 9: Sampling Distributions

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?

Retirees A sample of 50 retirees is drawn at random from a normal population whose mean age and standard deviation are 75 and 6 years,respectively. ​ ​ -{Retirees Narrative} What is the probability that the mean age exceeds 73 years?

Average Annual Revenue Suppose that the average annual revenue of a small business is $150,000 with a standard deviation of $40,000.Assume that the revenue distribution is normal. ​ ​ -{Average Annual Revenue Narrative} Why are your answers to the previous two questions different?

Retirees A sample of 50 retirees is drawn at random from a normal population whose mean age and standard deviation are 75 and 6 years,respectively. ​ ​ -{Retirees Narrative} What is the probability that two randomly selected retirees are over 73 years of age?

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?

Retirees A sample of 50 retirees is drawn at random from a normal population whose mean age and standard deviation are 75 and 6 years,respectively. ​ ​ -{Retirees Narrative} What is the probability that the mean age is at most 73 years?

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?

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. ​ ​ -{Poker Time Narrative} Find the probability that a randomly selected American adult plays Poker for more than 5 hours per week.

Heights of Fences Heights of fences are normally distributed with a mean of 52 inches and a standard deviation of 4 inches. ​ ​ -{Heights of Fence Narrative} Find the probability that two randomly selected fences are both under 54 inches.

Retirees A sample of 50 retirees is drawn at random from a normal population whose mean age and standard deviation are 75 and 6 years,respectively. ​ ​ -(Retirees Narrative} Find the mean and standard error of the sampling distribution of the sample mean.

Retirees A sample of 50 retirees is drawn at random from a normal population whose mean age and standard deviation are 75 and 6 years,respectively. ​ ​ -(Retirees Narrative} Describe the shape of the sampling distribution of the sample mean in this case.

Heights of Fences Heights of fences are normally distributed with a mean of 52 inches and a standard deviation of 4 inches. ​ ​ -{Heights of Fence Narrative} Find the probability that the mean height of 4 randomly selected fences is under 54 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} 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?

Retirees A sample of 50 retirees is drawn at random from a normal population whose mean age and standard deviation are 75 and 6 years,respectively. -{Retirees Narrative} What is the probability that the mean age exceeds 73 years?

Average Annual Revenue Suppose that the average annual revenue of a small business is $150,000 with a standard deviation of $40,000.Assume that the revenue distribution is normal. -{Average Annual Revenue Narrative} Why are your answers to the previous two questions different?

Retirees A sample of 50 retirees is drawn at random from a normal population whose mean age and standard deviation are 75 and 6 years,respectively. -{Retirees Narrative} What is the probability that two randomly selected retirees are over 73 years of age?

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?

Retirees A sample of 50 retirees is drawn at random from a normal population whose mean age and standard deviation are 75 and 6 years,respectively. -{Retirees Narrative} What is the probability that the mean age is at most 73 years?

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?

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. -{Poker Time Narrative} Find the probability that a randomly selected American adult plays Poker for more than 5 hours per week.

Heights of Fences Heights of fences are normally distributed with a mean of 52 inches and a standard deviation of 4 inches. -{Heights of Fence Narrative} Find the probability that two randomly selected fences are both under 54 inches.

Retirees A sample of 50 retirees is drawn at random from a normal population whose mean age and standard deviation are 75 and 6 years,respectively. -(Retirees Narrative} Find the mean and standard error of the sampling distribution of the sample mean.

Retirees A sample of 50 retirees is drawn at random from a normal population whose mean age and standard deviation are 75 and 6 years,respectively. -(Retirees Narrative} Describe the shape of the sampling distribution of the sample mean in this case.

Heights of Fences Heights of fences are normally distributed with a mean of 52 inches and a standard deviation of 4 inches. -{Heights of Fence Narrative} Find the probability that the mean height of 4 randomly selected fences is under 54 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} A random sample of five men is selected.What is the probability that the sample mean is greater than 70 inches?