Question 1

A sample of size 200 is taken at random from an infinite population.Given that the population proportion is 0.60,the probability that the sample proportion is greater than 0.58 is:

Accepted Answer

A) 0.281 
B) 0.719 
C) 0.580 
D) 0.762

Question 2

As n gets larger,the sampling distribution of  becomes increasingly bell shaped.This phenomenon is due to the ____________________.

Accepted Answer

The answer of As n gets larger,the sampling distribution of...

Question 3

CFO's Salary 
Suppose that the starting salaries of female CFO's have a positively skewed distribution with mean of $56,000 and a standard deviation of $12,000.The starting salaries of male CFO's are positively skewed with a mean of $50,000 and a standard deviation of $10,000.A random sample of 50 female CFO's and a random sample of 40 male CFO's are selected. ​ ​
-{CFO's Salary Narrative} Find the standard error of the sample mean difference.

Accepted Answer

The answer of CFO's Salary 
Suppose that the starting salaries...

Question 4

An infinite population has a mean of 40 and a standard deviation of 15.A sample of size 100 is taken at random from this population.The standard error of the sample mean equals:

Accepted Answer

A) 15 
B) 15/√100 
C) 15/100 
D) None of these choices.

Question 5

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

Accepted Answer

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

Question 6

The mean of the sampling distribution of the sample proportion,  ,when the sample size n = 100 and the population proportion p = 0.03,is 0.03.

Accepted Answer

A) True 
 B)False

Question 7

Graduate Internships
 The chairman of the Biology department in a certain college believes that 70% of the department's graduate internships are given to international students.A random sample of 50 graduate interns is taken. ​ ​
-{Graduate Internships Narrative} What is the probability that the sample proportion  is between 0.65 and 0.73?

Accepted Answer

The answer of  Graduate Internships
 The chairman of the...

Question 8

The standard error of the difference  is equal to the standard error of the difference  .

Accepted Answer

A) True 
 B)False

Question 9

In an effort to identify the true proportion of college freshman who are under 18 years of age,a random sample of 500 freshmen was taken.Fifty of them were under the age of 18.The value 0.10 is a point estimate of the true proportion of freshman under age 18.

Accepted Answer

A) True 
 B)False

Question 10

DVD Rental Store
 A DVD rental store wants to know what proportion of its customers are under age 21.A simple random sample of 500 customers was taken,and 375 of them were under age 21.Presume that the true population proportion of customers under age 21 is 0.68. ​ ​
-{DVD Rental Store Narrative} Describe the shape of the sampling distribution of proportion of customers who are under age 21.

Accepted Answer

The answer of DVD Rental Store
 A DVD rental store...

Question 11

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 salary...

Question 12

If all possible samples of size n are drawn from a population,the probability distribution of the sample mean  is called the:

Accepted Answer

A) standard error of  . 
B) expected value of  . 
C) sampling distribution of  . 
D) normal distribution.

Question 13

A sample of size 25 is selected from a population of size 75.The finite population correction needed to find the standard error of  .

Accepted Answer

A) True 
 B)False

Question 14

Magazines 
A local magazine store sells an average of 2,100 magazines per day,with a standard deviation of 500 magazines.Consider a sample of 60 days of operation.
-{Magazines Narrative} Find the expected value and the standard error of the sample mean.

Accepted Answer

The answer of  Magazines 
A local magazine store sells...

Question 15

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 16

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 17

Consider an infinite population with a mean of 160 and a standard deviation of 25.A random sample of size 64 is taken from this population.The standard deviation of the sample mean equals:

Accepted Answer

A) 25 
B) 25/64 
C) 25/√64 
D) None of these choices.

Question 18

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 19

If the population distribution is unknown,in most cases the sampling distribution of the mean can be approximated by the normal distribution if the samples contain at least 30 observations.

Accepted Answer

A) True 
 B)False

Question 20

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...

Exam 9: Sampling Distributions

A sample of size 200 is taken at random from an infinite population.Given that the population proportion is 0.60,the probability that the sample proportion is greater than 0.58 is:

As n gets larger,the sampling distribution of becomes increasingly bell shaped.This phenomenon is due to the ____________________.

An infinite population has a mean of 40 and a standard deviation of 15.A sample of size 100 is taken at random from this population.The standard error of the sample mean equals:

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

The mean of the sampling distribution of the sample proportion, ,when the sample size n = 100 and the population proportion p = 0.03,is 0.03.

The standard error of the difference is equal to the standard error of the difference .

In an effort to identify the true proportion of college freshman who are under 18 years of age,a random sample of 500 freshmen was taken.Fifty of them were under the age of 18.The value 0.10 is a point estimate of the true proportion of freshman under age 18.

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?

If all possible samples of size n are drawn from a population,the probability distribution of the sample mean is called the:

A sample of size 25 is selected from a population of size 75.The finite population correction needed to find the standard error of .

Magazines A local magazine store sells an average of 2,100 magazines per day,with a standard deviation of 500 magazines.Consider a sample of 60 days of operation. -{Magazines Narrative} Find the expected value and the standard error of the sample mean.

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.

Consider an infinite population with a mean of 160 and a standard deviation of 25.A random sample of size 64 is taken from this population.The standard deviation of the sample mean equals:

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

If the population distribution is unknown,in most cases the sampling distribution of the mean can be approximated by the normal distribution if the samples contain at least 30 observations.

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?

Exam 9: Sampling Distributions

A sample of size 200 is taken at random from an infinite population.Given that the population proportion is 0.60,the probability that the sample proportion is greater than 0.58 is:

As n gets larger,the sampling distribution of becomes increasingly bell shaped.This phenomenon is due to the ____________________.

An infinite population has a mean of 40 and a standard deviation of 15.A sample of size 100 is taken at random from this population.The standard error of the sample mean equals:

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

The mean of the sampling distribution of the sample proportion, ,when the sample size n = 100 and the population proportion p = 0.03,is 0.03.

The standard error of the difference is equal to the standard error of the difference .

In an effort to identify the true proportion of college freshman who are under 18 years of age,a random sample of 500 freshmen was taken.Fifty of them were under the age of 18.The value 0.10 is a point estimate of the true proportion of freshman under age 18.

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?

If all possible samples of size n are drawn from a population,the probability distribution of the sample mean is called the:

A sample of size 25 is selected from a population of size 75.The finite population correction needed to find the standard error of .

Magazines A local magazine store sells an average of 2,100 magazines per day,with a standard deviation of 500 magazines.Consider a sample of 60 days of operation. -{Magazines Narrative} Find the expected value and the standard error of the sample mean.

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.

Consider an infinite population with a mean of 160 and a standard deviation of 25.A random sample of size 64 is taken from this population.The standard deviation of the sample mean equals:

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

If the population distribution is unknown,in most cases the sampling distribution of the mean can be approximated by the normal distribution if the samples contain at least 30 observations.

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?

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

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?