Question 1

The sampling distribution of the sample mean   is the distribution of all possible sample means that could be computed from all possible sample of a given size n.

Accepted Answer

A) True 
 B)False

Question 2

The mean of the sampling distribution of the sample proportion   when n = 100 and p = 0.5 is 5.0.

Accepted Answer

A) True 
 B)False

Question 3

If all possible samples of size n are drawn from a large population with a mean of 20 and a standard deviation of 5, then the standard error of the sample mean equals 1.0 only for samples of size:

Accepted Answer

A)  15 
B)  20 
C)  25 
D)  30 
E)  35 
A)  15 
B)  20 
C)  25 
D)  30 
E)  35

Question 4

If a population standard deviation is equal to 24.8, then the sampling distribution of the sample mean   will have a standard deviation that is less than 24.8 for all possible sample sizes.

Accepted Answer

A) True 
 B)False

Question 5

On a particular freeway in Michigan, it is reported that the proportion of cars that exceed the speed limit is 0.15. Given this information, the probability that a sample of 250 cars will have a sample proportion below 0.12 is approximately .0918.

Accepted Answer

A) True 
 B)False

Question 6

The cause of a change in a process variable being monitored is regarded as random variation if it can be found and corrected.

Accepted Answer

A) True 
 B)False

Question 7

The proportion of individuals with an Rh-positive blood type is 88%. You have a random sample of n = 500 individuals.
What is the mean of   , the sample proportion with Rh-positive blood type?
______________
What is the standard deviation?
______________
Is the distribution approximately normal?
______________
What is the probability that the sample proportion exceeds 85%.
______________
What is the probability that the sample proportion   lies between 86% and 91%?
______________
99% of the time, the sample proportion   would lie between what two limits?
Lower Limit = ______________
Upper Limit = ______________

Accepted Answer

0.88; 0.01

Question 8

The sampling distribution of the sample mean is exactly normally distributed, regardless of the sample size n.

Accepted Answer

A) True 
 B)False

Question 9

Given a population variance of   = 36 and a sample size of n = 9, these imply a standard deviation of the sampling distribution of the sample mean,   , of:

Accepted Answer

A)  4 
B)  2 
C)  1/4 
D)  1/2 
A)  4 
B)  2 
C)  1/4 
D)  1/2

Question 10

For a   control chart, the lower and upper control limits are usually set at:

Accepted Answer

A)  one standard deviation from the centerline 
B)  two standard deviations from the centerline 
C)  three standard deviations from the centerline 
D)  four standard deviations from the centerline 
E)  five standard deviations from the centerline 
A)  one standard deviation from the centerline 
B)  two standard deviations from the centerline 
C)  three standard deviations from the centerline 
D)  four standard deviations from the centerline 
E)  five standard deviations from the centerline

Question 11

The amount of time to complete a particular exam is believed to have a mean of 52 minutes and a standard deviation of 4.8 minutes. A sample of 36 students was selected and their times to finish the exam recorded.
Is the sampling distribution of the sample mean approximately normal?
______________
What is the mean?
______________
What is the standard deviation?
______________
What is the probability this sample produces an average of less than 50 minutes?
______________
If the sample mean   is actually 50 minutes, is it likely that   = 52?
______________
Explain.
________________________________________________________

Accepted Answer

Yes; 52; 0.80; 0.006

Question 12

The mean of the sample means and the standard deviation of 50 samples of size 5 taken from a production process under control are found to be 300 and 25, respectively. The lower control limit for the   chart is located at:

Accepted Answer

A)  333.54 
B)  289.39 
C)  310.61 
D)  266.46 
E)  342.88 
A)  333.54 
B)  289.39 
C)  310.61 
D)  266.46 
E)  342.88

Question 13

Assume that the proportion of defective items in a sample of 400 items is 0.20.
Is the normal approximation to the sampling distribution of   appropriate in this situation?
______________
Find the probability that   is greater than 0.23.
______________
Find the probability that   lies between 0.16 and 0.24.
______________

Accepted Answer

The answer of Assume that the proportion of defective items...

Question 14

A candy bar factory is pouring chocolate into molds to cool. The finished bars are sold as 1.25 ounce bars. The company will lose money if the molds are over-filled. If the molds are under-filled, the weight of the candy bars will be less than the wrapper label says, and the Food and Drug Administration will fine the company for misrepresenting the size of its product. The company wants to create an   chart to monitor the weight of the candy bars. Suppose there are 5 samples of size 30 each taken, and their sample means are 1.27, 1.22, 1.26, 1.23, and 1.26 ounces.
What is the centerline value?
______________
The calculated value of s, the sample standard deviation of all nk = (30)(5) = 150 observations, is 0.12 ounces. What is the standard error of the mean of 30 observations?
______________
What are the control limits?
UCL = ______________
LCL = ______________
How is the   chart used in this situation?
________________________________________________________

Accepted Answer

1.248; 0.0219; 1.3137; 1.1823;

Question 15

A list of commonly used parameters includes:

Accepted Answer

A)  the sample mean 
B)  the sample standard deviation, s 
C)  the sample proportion 
D)  all of these 
E)  none of these 
A)  the sample mean 
B)  the sample standard deviation, s 
C)  the sample proportion 
D)  all of these 
E)  none of these

Question 16

Random samples of size 36 each are taken from a large population whose mean is 120 and standard deviation is 39. The mean and standard error of the sampling distribution of sample mean, respectively, are:

Accepted Answer

A)  120 and 39 
B)  120 and 6.5 
C)  120 and 5.5 
D)  39 and 120 
E)  6.5 and 120 
A)  120 and 39 
B)  120 and 6.5 
C)  120 and 5.5 
D)  39 and 120 
E)  6.5 and 120

Question 17

Given a population proportion of p = .8 and a sample size of n = 100, these imply a standard deviation of the sampling distribution of the sample proportion   of:

Accepted Answer

A)  .0258 
B)  .0355 
C)  .0400 
D)  .0538 
E)  none of these 
A)  .0258 
B)  .0355 
C)  .0400 
D)  .0538 
E)  none of these

Question 18

If a process is in control, we expect all the data values to fall within three standard deviations of the mean.

Accepted Answer

A) True 
 B)False

Question 19

Assignable cause variation is also called:

Accepted Answer

A)  random variation 
B)  special cause variation 
C)  common cause variation 
D)  within-group variation 
E)  none of these 
A)  random variation 
B)  special cause variation 
C)  common cause variation 
D)  within-group variation 
E)  none of these

Question 20

A summary measure calculated for a population is called a parameter and is designated by Greek letters (such as   for mean or   for proportion).

Accepted Answer

A) True 
 B)False

The sampling distribution of the sample mean is the distribution of all possible sample means that could be computed from all possible sample of a given size n.

The mean of the sampling distribution of the sample proportion when n = 100 and p = 0.5 is 5.0.

If all possible samples of size n are drawn from a large population with a mean of 20 and a standard deviation of 5, then the standard error of the sample mean equals 1.0 only for samples of size:

If a population standard deviation is equal to 24.8, then the sampling distribution of the sample mean will have a standard deviation that is less than 24.8 for all possible sample sizes.

On a particular freeway in Michigan, it is reported that the proportion of cars that exceed the speed limit is 0.15. Given this information, the probability that a sample of 250 cars will have a sample proportion below 0.12 is approximately .0918.

The cause of a change in a process variable being monitored is regarded as random variation if it can be found and corrected.

The sampling distribution of the sample mean is exactly normally distributed, regardless of the sample size n.

Given a population variance of = 36 and a sample size of n = 9, these imply a standard deviation of the sampling distribution of the sample mean, , of:

For a control chart, the lower and upper control limits are usually set at:

The mean of the sample means and the standard deviation of 50 samples of size 5 taken from a production process under control are found to be 300 and 25, respectively. The lower control limit for the chart is located at:

Assume that the proportion of defective items in a sample of 400 items is 0.20. Is the normal approximation to the sampling distribution of appropriate in this situation? Find the probability that is greater than 0.23. Find the probability that lies between 0.16 and 0.24. __

A list of commonly used parameters includes:

Random samples of size 36 each are taken from a large population whose mean is 120 and standard deviation is 39. The mean and standard error of the sampling distribution of sample mean, respectively, are:

Given a population proportion of p = .8 and a sample size of n = 100, these imply a standard deviation of the sampling distribution of the sample proportion of:

If a process is in control, we expect all the data values to fall within three standard deviations of the mean.

Assignable cause variation is also called:

A summary measure calculated for a population is called a parameter and is designated by Greek letters (such as for mean or for proportion).

Describing Data With Graphs

Describing Data With Numerical Measures

Describing Bivariate Data

Probability and Probability Distributions

Several Useful Discrete Distributions

The Normal Probability Distribution

Large-Sample Estimation

Large-Sample Tests of Hypotheses

Inference From Small Samples

The Analysis of Variance

Linear Regression and Correlation

Multiple Regression Analysis

Analysis of Categorical Data

Nonparametric Statistics

Filters

Exam 7: Sampling Distributions

The sampling distribution of the sample mean is the distribution of all possible sample means that could be computed from all possible sample of a given size n.

The mean of the sampling distribution of the sample proportion when n = 100 and p = 0.5 is 5.0.

If all possible samples of size n are drawn from a large population with a mean of 20 and a standard deviation of 5, then the standard error of the sample mean equals 1.0 only for samples of size:

If a population standard deviation is equal to 24.8, then the sampling distribution of the sample mean will have a standard deviation that is less than 24.8 for all possible sample sizes.

On a particular freeway in Michigan, it is reported that the proportion of cars that exceed the speed limit is 0.15. Given this information, the probability that a sample of 250 cars will have a sample proportion below 0.12 is approximately .0918.

The cause of a change in a process variable being monitored is regarded as random variation if it can be found and corrected.

The sampling distribution of the sample mean is exactly normally distributed, regardless of the sample size n.

Given a population variance of = 36 and a sample size of n = 9, these imply a standard deviation of the sampling distribution of the sample mean, , of:

For a control chart, the lower and upper control limits are usually set at:

The mean of the sample means and the standard deviation of 50 samples of size 5 taken from a production process under control are found to be 300 and 25, respectively. The lower control limit for the chart is located at:

A list of commonly used parameters includes:

Random samples of size 36 each are taken from a large population whose mean is 120 and standard deviation is 39. The mean and standard error of the sampling distribution of sample mean, respectively, are:

Given a population proportion of p = .8 and a sample size of n = 100, these imply a standard deviation of the sampling distribution of the sample proportion of:

If a process is in control, we expect all the data values to fall within three standard deviations of the mean.

Assignable cause variation is also called:

A summary measure calculated for a population is called a parameter and is designated by Greek letters (such as for mean or for proportion).

Describing Data With Graphs

Describing Data With Numerical Measures

Describing Bivariate Data

Probability and Probability Distributions

Several Useful Discrete Distributions

The Normal Probability Distribution

Large-Sample Estimation

Large-Sample Tests of Hypotheses

Inference From Small Samples

The Analysis of Variance

Linear Regression and Correlation

Multiple Regression Analysis

Analysis of Categorical Data

Nonparametric Statistics

Filters