Question 1

For a sample size of 1,the sampling distribution of the mean is normally distributed:

Accepted Answer

A)  regardless of the shape of the population. 
B)  only if the population values are larger than 30. 
C)  only if the population is normally distributed. 
D)  None of these choices. 
A)  regardless of the shape of the population. 
B)  only if the population values are larger than 30. 
C)  only if the population is normally distributed. 
D)  None of these choices.

Question 2

As the number of throws of a fair die increases,the probability that the sample mean is close to (the number)____________________ increases.

Accepted Answer

The answer of As the number of throws of a...

Question 3

The mean of the sampling distribution of the sample proportion $\hat { p }$ ,when the sample size n = 100 and the population proportion p = 0.92,is 92.0.

Accepted Answer

A) True 
 B)False

Question 4

A sample of size 25 is selected at random from a finite population.If the finite population correction factor is 0.63,then the population size is:

Accepted Answer

A)  25 
B)  66 
C)  41 
D)  None of these choices. 
A)  25 
B)  66 
C)  41 
D)  None of these choices.

Question 5

Given that X is a binomial random variable with very large n,the binomial probability P(X $\ge$  5)is approximated by the area under a normal curve to the right of

Accepted Answer

A)  4.5 
B)  5.5 
C)  4 
D)  6 
A)  4.5 
B)  5.5 
C)  4 
D)  6

Question 6

A sample of size 40 is taken from an infinite population whose mean and standard deviation are 68 and 12,respectively.The probability that the sample mean is larger than 70 equals

Accepted Answer

A)  P(Z > 70) 
B)  P(Z > 2) 
C)  P(Z > 0.17) 
D)  P(Z > 1.05) 
A)  P(Z > 70) 
B)  P(Z > 2) 
C)  P(Z > 0.17) 
D)  P(Z > 1.05)

Question 7

As n gets ____________________,the shape of the sampling distribution of $\bar { X }$ becomes increasingly bell shaped.

Accepted Answer

The answer of As n gets ____________________,the shape of the...

Question 8

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

@#LAT-DLM& = $121.448 and $126.491 with

Question 9

College Dean
A college dean would like to estimate a population mean to within 40 units with 99% confidence given that the population standard deviation is 200.
-The Central Limit Theorem permits us to draw conclusions about a population based on a sample alone,without having any knowledge about the distribution of that population.And this works no matter what the sample size is.

Accepted Answer

A) True 
 B)False

Question 10

As a general rule in computing the standard error of the sample mean,the finite population correction factor is used only if the:

Accepted Answer

A)  sample size is smaller than 5% of the population size. 
B)  sample size is greater than 5% of the sample size. 
C)  sample size is more than half of the population size. 
D)  None of these choices. 
A)  sample size is smaller than 5% of the population size. 
B)  sample size is greater than 5% of the sample size. 
C)  sample size is more than half of the population size. 
D)  None of these choices.

Question 11

If two random samples of sizes 30 and 32 are selected independently from two populations with means 121 and 109,then the mean of the sampling distribution of the sample mean difference, $\bar { X } _ { 1 } - \bar { X } _ { 2 }$ ,equals 12.

Accepted Answer

A) True 
 B)False

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 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 by...

Question 13

The width of the sampling distribution of $\bar { X }$ gets ____________________ as the sample size increases.

Accepted Answer

narrower
m

Question 14

A randomly selected value of $\bar { X }$ is likely to be ____________________ to(than)the mean of the population than is a randomly selected value of X.

Accepted Answer

The answer of A randomly selected value of \(\bar {...

Question 15

A sampling distribution is a probability distribution for a statistic,not a parameter.

Accepted Answer

A) True 
 B)False

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} 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 17

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/$\surd$100 
C)  15/100 
D)  None of these choices. 
A)  15 
B)  15/$\surd$100 
C)  15/100 
D)  None of these choices.

Question 18

The amount of bleach a machine pours into bottles has a mean of 50 ounces with a standard deviation of 0.25 ounces.Suppose we take a random sample of 36 bottles filled by this machine.The sampling distribution of the sample mean has a standard error of 0.25 ounces.

Accepted Answer

A) True 
 B)False

Question 19

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} Assume that the chairman is correct and p = 0.70.What is the sampling distribution of the sample proportion $\hat { p }$ ? Explain.

Accepted Answer

Approximately normal

Question 20

As a general rule,the normal distribution is used to approximate the sampling distribution of the sample proportion only if the sample size n is greater than or equal to 30.

Accepted Answer

A) True 
 B)False

Exam 9: Sampling Distributions

For a sample size of 1,the sampling distribution of the mean is normally distributed:

As the number of throws of a fair die increases,the probability that the sample mean is close to (the number)____________________ increases.

The mean of the sampling distribution of the sample proportion p^\hat { p }p^​ ,when the sample size n = 100 and the population proportion p = 0.92,is 92.0.

A sample of size 25 is selected at random from a finite population.If the finite population correction factor is 0.63,then the population size is:

Given that X is a binomial random variable with very large n,the binomial probability P(X ≥\ge≥ 5)is approximated by the area under a normal curve to the right of

A sample of size 40 is taken from an infinite population whose mean and standard deviation are 68 and 12,respectively.The probability that the sample mean is larger than 70 equals

As n gets ____________________,the shape of the sampling distribution of Xˉ\bar { X }Xˉ becomes increasingly bell shaped.

As a general rule in computing the standard error of the sample mean,the finite population correction factor is used only if the:

If two random samples of sizes 30 and 32 are selected independently from two populations with means 121 and 109,then the mean of the sampling distribution of the sample mean difference, Xˉ1−Xˉ2\bar { X } _ { 1 } - \bar { X } _ { 2 }Xˉ1​−Xˉ2​ ,equals 12.

The width of the sampling distribution of Xˉ\bar { X }Xˉ gets ____________________ as the sample size increases.

A randomly selected value of Xˉ\bar { X }Xˉ is likely to be ____________________ to(than)the mean of the population than is a randomly selected value of X.

A sampling distribution is a probability distribution for a statistic,not a parameter.

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?

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:

The amount of bleach a machine pours into bottles has a mean of 50 ounces with a standard deviation of 0.25 ounces.Suppose we take a random sample of 36 bottles filled by this machine.The sampling distribution of the sample mean has a standard error of 0.25 ounces.

As a general rule,the normal distribution is used to approximate the sampling distribution of the sample proportion only if the sample size n is greater than or equal to 30.

What Is Statistics

Graphical Descriptive Techniques I

Graphical Descriptive Techniques II

A: Numerical Descriptive Techniques

B: Numerical Descriptive Techniques

C: Numerical Descriptive Techniques

Data Collection and Sampling

Probability

A: Random Variables and Discrete Probability Distributions

B: Random Variables and Discrete Probability Distributions

Continuous Probability Distributions

Introduction to Estimation

Introduction to Hypothesis Testing

Inference About a Population

Inference About Comparing Two Populations

Analysis of Variance

Chi-Squared Tests

A: Simple Linear Regression and Correlation

B: Simple Linear Regression and Correlation

Multiple Regression

Model Building

Nonparametric Statistics

Time-Series Analysis and Forecasting

Statistical Process Control

Decision Analysis

Conclusion

Filters

The mean of the sampling distribution of the sample proportion $\hat { p }$ ,when the sample size n = 100 and the population proportion p = 0.92,is 92.0.

Given that X is a binomial random variable with very large n,the binomial probability P(X $\ge$ 5)is approximated by the area under a normal curve to the right of

As n gets ____________________,the shape of the sampling distribution of $\bar { X }$ becomes increasingly bell shaped.

If two random samples of sizes 30 and 32 are selected independently from two populations with means 121 and 109,then the mean of the sampling distribution of the sample mean difference, $\bar { X } _ { 1 } - \bar { X } _ { 2 }$ ,equals 12.

The width of the sampling distribution of $\bar { X }$ gets ____________________ as the sample size increases.

A randomly selected value of $\bar { X }$ is likely to be ____________________ to(than)the mean of the population than is a randomly selected value of X.