Question 1

Based on the formula   we can assume that the point estimate   of the population mean   will be at the center of the confidence interval estimate.

Accepted Answer

A) True 
 B)False

Question 2

A dieter believes that the average number of calories in a homemade peanut butter cookie is more than in a store-bought peanut butter cookie. The summary data are listed below.   Estimate the difference in the mean calories between the two types of cookies using a 90% confidence interval.
______________

Accepted Answer

The answer of A dieter believes that the average number...

Question 3

A machine produces aluminum tins used in packaging cheese. A random sample of 1000 tins was selected and 43 were found to be defective. Find a 95% upper confidence bound for the true proportion of defective tins produced by the machine.
______________

Accepted Answer

The answer of A machine produces aluminum tins used in...

Question 4

Estimation is best defined as:

Accepted Answer

A)  a process of inferring the values of unknown population parameters from those of known sample statistics 
B)  a process of inferring the values of unknown samples statistics from those of known population parameters 
C)  any procedure that views the parameter being estimated not as a constant, but, just like the estimator, as a random variable 
D)  a sampling procedure that matches each unit from population A with a "twin" from population B so that any sample observation about a unit in population A automatically yields an associated observation about a unit in population B 
E)  both a process of inferring the values of unknown samples statistics from those of known population parameters and any procedure that views the parameter being estimated not as a constant, but, just like the estimator, as a random variable 
A)  a process of inferring the values of unknown population parameters from those of known sample statistics 
B)  a process of inferring the values of unknown samples statistics from those of known population parameters 
C)  any procedure that views the parameter being estimated not as a constant, but, just like the estimator, as a random variable 
D)  a sampling procedure that matches each unit from population A with a "twin" from population B so that any sample observation about a unit in population A automatically yields an associated observation about a unit in population B 
E)  both a process of inferring the values of unknown samples statistics from those of known population parameters and any procedure that views the parameter being estimated not as a constant, but, just like the estimator, as a random variable

Question 5

Which of the following statements is correct?

Accepted Answer

A)  A point estimate is an estimate of the range of a population parameter. 
B)  An interval estimate is an estimate of the range for a sample statistic. 
C)  A point estimate is a single value estimate of the value of a population parameter. 
D)  An interval estimate is an estimate of the value of a population parameter. 
E)  A point estimate is an estimate of the midpoint of the range for a sample statistic. 
A)  A point estimate is an estimate of the range of a population parameter. 
B)  An interval estimate is an estimate of the range for a sample statistic. 
C)  A point estimate is a single value estimate of the value of a population parameter. 
D)  An interval estimate is an estimate of the value of a population parameter. 
E)  A point estimate is an estimate of the midpoint of the range for a sample statistic.

Question 6

Instead of paying to support welfare recipients, many Californians want them to find jobs; if necessary, they want the state to create public service jobs for those who cannot find jobs in private industry. In a survey of 800 registered voters, 400 Republicans and 400 Democrats, 75% of the Republicans and 90% of the Democrats favored the creation of public service jobs. Use a large-sample estimation procedure to compare the proportions of Republicans and Democrats who favor creating public service jobs in the population of registered voters in California.
The approximate 95% confidence interval is:
______________
Based on the interval above, is there a difference in the proportion of Republicans and Democrats who favor creating public service jobs in California?
______________
Explain.
________________________________________________________

Accepted Answer

(-0.2015, -0.0985); Yes; Since the value

Question 7

If you wish to construct 85% upper confidence bound (UCB) for the population proportion p, then the z-value you should use is approximately:

Accepted Answer

A)  2.58 
B)  2.33 
C)  1.96 
D)  1.65 
E)  1.04 
A)  2.58 
B)  2.33 
C)  1.96 
D)  1.65 
E)  1.04

Question 8

One way to reduce the margin of error in a confidence interval is to decrease the confidence coefficient.

Accepted Answer

A) True 
 B)False

Question 9

An airport bus driver conducted a study to see what proportion of customers use the shuttle bus to get to and from the parking lot. The results of his study are listed below, where B = customer used the bus and W = customer walked.   Construct a 95% confidence interval for p, the true proportion of all people who used the bus.
______________
Construct a 90% confidence interval for p, the true proportion of all people who used the bus.
______________

Accepted Answer

(0.488, 0.

Question 10

If you wish to construct 98% upper confidence bound (UCB) for the difference between population proportions, then the approximate z-value you should use is:

Accepted Answer

A)  2.33 
B)  2.05 
C)  1.96 
D)  1.65 
E)  1.41 
A)  2.33 
B)  2.05 
C)  1.96 
D)  1.65 
E)  1.41

Question 11

In developing an interval estimate for the population mean   , the population standard deviation   was assumed to be 6. The interval estimate was 45.0   1.5. Had   equaled 12, the interval estimate would be 90   3.

Accepted Answer

A) True 
 B)False

Question 12

An interval estimate is an interval that provides an upper and lower bound for a specific population parameter whose value is unknown.

Accepted Answer

A) True 
 B)False

Question 13

The confidence coefficient is the probability that a confidence interval will enclose the estimated parameter.

Accepted Answer

A) True 
 B)False

Question 14

The role of the sample mean   in a confidence interval estimate for the population mean   is to determine:

Accepted Answer

A)  the sample size needed 
B)  the confidence coefficient 1 - 
C)  the margin of error in the estimate 
D)  all of these 
E)  none of these 
A)  the sample size needed 
B)  the confidence coefficient 1 - 
C)  the margin of error in the estimate 
D)  all of these 
E)  none of these

Question 15

Which of the following statements is false?

Accepted Answer

A)  The width of a confidence interval estimate of the population mean narrows when the sample size increases. 
B)  The width of a confidence interval estimate of the population mean narrows when the value of the sample mean increases. 
C)  The width of a confidence interval estimate of the population mean widens when the confidence level increases. 
D)  Both "The width of a confidence interval estimate of the population mean narrows when the sample size increases" and "The width of a confidence interval estimate of the population mean widens when the confidence level increases." 
E)  None of these. 
A)  The width of a confidence interval estimate of the population mean narrows when the sample size increases. 
B)  The width of a confidence interval estimate of the population mean narrows when the value of the sample mean increases. 
C)  The width of a confidence interval estimate of the population mean widens when the confidence level increases. 
D)  Both "The width of a confidence interval estimate of the population mean narrows when the sample size increases" and "The width of a confidence interval estimate of the population mean widens when the confidence level increases." 
E)  None of these.

Question 16

If a 90% confidence interval estimate for the difference between two population proportions is to be constructed, then the confidence coefficient would be:

Accepted Answer

A)  .10 
B)  .90 
C)  .05 
D)  .45 
E)  .35 
A)  .10 
B)  .90 
C)  .05 
D)  .45 
E)  .35

Question 17

An experiment was conducted to compare two diets A and B designed for weight reduction. Two groups of 50 overweight dieters each were randomly selected. One group was placed on diet A and the other on diet B, and their weight losses were recorded over a 30-day period. The means and standard deviations of the weight-loss measurements for the two groups are shown in the table.   Find a 95% confidence interval for the difference in mean weight loss for the two diets.
______________
Interpret the interval.
________________________________________________________

Accepted Answer

(7.0654, 8.7346); One can estimate with

Question 18

In a study of the relationship between birth order and college success, an investigator found that 140 in a sample of 200 college graduates were firstborn or only children. In a sample of 120 non-graduates of comparable age and socioeconomic background, the number of firstborn or only children was 66. Estimate the difference between the proportions of firstborn or only children in the two populations from which these samples were drawn. Use a 90% confidence interval and interpret your results.
The approximate 90% confidence interval is:
______________
Based on the interval above, is there a difference between the proportions of firstborn or only children in the two populations?
______________
Explain.
________________________________________________________

Accepted Answer

(0.058, 0.242); No; One can estimate wit

Question 19

If the population variance is increased and other factors are the same, the width of a confidence interval for the population mean tends to increase.

Accepted Answer

A) True 
 B)False

Question 20

Assume that two independent random samples of sizes   and   have been selected from binomial populations with parameters   and   , respectively. The sampling distribution of   , the difference between sample proportions, can be approximated by a normal distribution provided that   , and   are all greater than 5.

Accepted Answer

A) True 
 B)False

Based on the formula we can assume that the point estimate of the population mean will be at the center of the confidence interval estimate.

A machine produces aluminum tins used in packaging cheese. A random sample of 1000 tins was selected and 43 were found to be defective. Find a 95% upper confidence bound for the true proportion of defective tins produced by the machine. ______________

Estimation is best defined as:

Which of the following statements is correct?

If you wish to construct 85% upper confidence bound (UCB) for the population proportion p, then the z-value you should use is approximately:

One way to reduce the margin of error in a confidence interval is to decrease the confidence coefficient.

If you wish to construct 98% upper confidence bound (UCB) for the difference between population proportions, then the approximate z-value you should use is:

In developing an interval estimate for the population mean , the population standard deviation was assumed to be 6. The interval estimate was 45.0 1.5. Had equaled 12, the interval estimate would be 90 3.

An interval estimate is an interval that provides an upper and lower bound for a specific population parameter whose value is unknown.

The confidence coefficient is the probability that a confidence interval will enclose the estimated parameter.

The role of the sample mean in a confidence interval estimate for the population mean is to determine:

Which of the following statements is false?

If a 90% confidence interval estimate for the difference between two population proportions is to be constructed, then the confidence coefficient would be:

If the population variance is increased and other factors are the same, the width of a confidence interval for the population mean tends to increase.

Assume that two independent random samples of sizes and have been selected from binomial populations with parameters and , respectively. The sampling distribution of , the difference between sample proportions, can be approximated by a normal distribution provided that , and are all greater than 5.

Describing Data With Graphs

Describing Data With Numerical Measures

Describing Bivariate Data

Probability and Probability Distributions

Several Useful Discrete Distributions

The Normal Probability Distribution

Sampling Distributions

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 8: Large-Sample Estimation

Based on the formula we can assume that the point estimate of the population mean will be at the center of the confidence interval estimate.

A machine produces aluminum tins used in packaging cheese. A random sample of 1000 tins was selected and 43 were found to be defective. Find a 95% upper confidence bound for the true proportion of defective tins produced by the machine. ______________

Estimation is best defined as:

Which of the following statements is correct?

If you wish to construct 85% upper confidence bound (UCB) for the population proportion p, then the z-value you should use is approximately:

One way to reduce the margin of error in a confidence interval is to decrease the confidence coefficient.

If you wish to construct 98% upper confidence bound (UCB) for the difference between population proportions, then the approximate z-value you should use is:

In developing an interval estimate for the population mean , the population standard deviation was assumed to be 6. The interval estimate was 45.0 1.5. Had equaled 12, the interval estimate would be 90 3.

An interval estimate is an interval that provides an upper and lower bound for a specific population parameter whose value is unknown.

The confidence coefficient is the probability that a confidence interval will enclose the estimated parameter.

The role of the sample mean in a confidence interval estimate for the population mean is to determine:

Which of the following statements is false?

If a 90% confidence interval estimate for the difference between two population proportions is to be constructed, then the confidence coefficient would be:

If the population variance is increased and other factors are the same, the width of a confidence interval for the population mean tends to increase.

Assume that two independent random samples of sizes and have been selected from binomial populations with parameters and , respectively. The sampling distribution of , the difference between sample proportions, can be approximated by a normal distribution provided that , and are all greater than 5.

Describing Data With Graphs

Describing Data With Numerical Measures

Describing Bivariate Data

Probability and Probability Distributions

Several Useful Discrete Distributions

The Normal Probability Distribution

Sampling Distributions

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