Question 1

A 90% upper confidence bound (UCB) for the population proportion p can be constructed using the following equation:
UCB =

Accepted Answer

A) True 
 B)False

Question 2

The two limits that define an interval estimate are known as confidence limits.

Accepted Answer

A) True 
 B)False

Question 3

A 90% confidence interval estimate for a population mean   is determined to be 62.8 to 73.4. If the confidence level is reduced to 80%, the confidence interval for   becomes narrower.

Accepted Answer

A) True 
 B)False

Question 4

The margin of error is:

Accepted Answer

A)  the difference between the point estimate and the true value of the population parameter 
B)  the critical value times the standard error of the estimator 
C)  the smallest possible sampling error 
D)  both the difference between the point estimate and the true value of the population parameter and the critical value times the standard error of the estimator 
E)  none of these 
A)  the difference between the point estimate and the true value of the population parameter 
B)  the critical value times the standard error of the estimator 
C)  the smallest possible sampling error 
D)  both the difference between the point estimate and the true value of the population parameter and the critical value times the standard error of the estimator 
E)  none of these

Question 5

The concept of margin of error applies directly when estimating the population mean   , but is not applicable when estimating the population proportion p.

Accepted Answer

A) True 
 B)False

Question 6

A stylist at The Hair Care Palace gathered data on the number of hair colorings given on Saturdays and on weekdays. Her results are listed below. Assume the two samples were independently taken from normal populations.   Find the point estimate of p1 - p2.
______________
Find the margin of error.
______________
Estimate the difference in the true proportions with a 99% confidence interval.
______________
Interpret this interval.
________________________________________________________

Accepted Answer

0.08; 0.158; (-0.128, 0.288);

Question 7

Which of the following is a parameter?

Accepted Answer

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

Question 8

In developing an interval estimate for a population mean, the population standard deviation   was 8. The interval estimate was 40.52   3.24. Had   equaled 16, the interval estimate would be:

Accepted Answer

A)  40.5211.24 
B)  48.5211.24 
C)  81.0411.24 
D)  40.526.48 
E)  81.046.48 
A)  40.5211.24 
B)  48.5211.24 
C)  81.0411.24 
D)  40.526.48 
E)  81.046.48

Question 9

Suppose that a 95% confidence interval for the population proportion p is given by   . This notation means that we are 95% confident that p falls between   and   .

Accepted Answer

A) True 
 B)False

Question 10

Those who engage in estimation insist on random sampling, rather than convenience sampling or judgment sampling, because random sampling:

Accepted Answer

A)  avoids the errors inherent in matched-pairs sampling 
B)  avoids the errors inherent in work sampling 
C)  avoids the errors inherent in voluntary response sampling 
D)  eliminates the systematic error or bias that arises in nonrandom sampling 
E)  achieves all of these 
A)  avoids the errors inherent in matched-pairs sampling 
B)  avoids the errors inherent in work sampling 
C)  avoids the errors inherent in voluntary response sampling 
D)  eliminates the systematic error or bias that arises in nonrandom sampling 
E)  achieves all of these

Question 11

For a given sample size and given confidence coefficient, the closer the population proportion p to 1.0, the greater the margin of error will be.

Accepted Answer

A) True 
 B)False

Question 12

A study was conducted to compare the mean numbers of police emergency calls per 8-hour shift in two districts of Los Angeles. Samples of 100 8-shifts were randomly selected from the police records for each of the two regions, and the number of emergency calls was recorded for each shift. The sample statistics are listed below:   Find a 90% confidence interval for the difference in the mean numbers of police emergency calls per shift between the two districts of the city.
______________
Interpret the interval.
________________________________________________________

Accepted Answer

(-1.0482, -0.3518); One can estimate wit

Question 13

A random sample of n = 50 observations from a quantitative population produced   = 65.4 and s2 = 2.8.
Give the best point estimate for the population mean,   .
______________
Calculate the margin of error.
______________

Accepted Answer

Question 14

The manufacturer of a particular battery pack for a laptop computer claims the battery pack can function for 8 hours, on the average, before having to be recharged. A random sample of 36 such battery packs was selected and tested. The mean and standard deviation were found to be 6 hours and 1.8 hours, respectively.
Find a 95% lower confidence bound for the true average time the battery pack can function before having to be recharged.
______________

Accepted Answer

The answer of The manufacturer of a particular battery pack...

Question 15

Suppose a 95% confidence interval for the mean height of a 12-year-old male in the United States is 54 to 65 inches. In repeated sampling, 95% of the intervals constructed will contain the interval from 54 to 65 inches.

Accepted Answer

A) True 
 B)False

Question 16

The wider the confidence interval, the more likely it is that the interval contains the true value of the population parameter.

Accepted Answer

A) True 
 B)False

Question 17

A statistic is said to be unbiased if its sampling distribution has the smallest standard error.

Accepted Answer

A) True 
 B)False

Question 18

A recent survey indicates that the proportion of season ticket holders for Ferris State University hockey team that renew their seats is about .80. Using this information, the sample size that is needed to estimate the true proportion that plan to renew their seats using 95% confidence and a margin of error of   .025 is about:

Accepted Answer

A)  689 
B)  697 
C)  810 
D)  984 
E)  1,179 
A)  689 
B)  697 
C)  810 
D)  984 
E)  1,179

Question 19

A proportion of a college basketball team's season ticket holders renew their tickets for the next season. Let p denote the true proportion of ticket holders who buy tickets again for the following season. A random sample of 125 ticket holders revealed 90 people plan on renewing their tickets. Give a point estimate for p and find the estimated margin of error.
The point estimate is: ______________
The margin of error is: ______________

Accepted Answer

The answer of A proportion of a college basketball team's...

Question 20

A 90% confidence interval for the population mean   is found to be between 5.28 and 6.72. Based on this information, the sample mean   that generated the confidence interval was 6.

Accepted Answer

A) True 
 B)False

A 90% upper confidence bound (UCB) for the population proportion p can be constructed using the following equation: UCB =

The two limits that define an interval estimate are known as confidence limits.

A 90% confidence interval estimate for a population mean is determined to be 62.8 to 73.4. If the confidence level is reduced to 80%, the confidence interval for becomes narrower.

The margin of error is:

The concept of margin of error applies directly when estimating the population mean , but is not applicable when estimating the population proportion p.

Which of the following is a parameter?

In developing an interval estimate for a population mean, the population standard deviation was 8. The interval estimate was 40.52 3.24. Had equaled 16, the interval estimate would be:

Suppose that a 95% confidence interval for the population proportion p is given by . This notation means that we are 95% confident that p falls between and .

Those who engage in estimation insist on random sampling, rather than convenience sampling or judgment sampling, because random sampling:

For a given sample size and given confidence coefficient, the closer the population proportion p to 1.0, the greater the margin of error will be.

A random sample of n = 50 observations from a quantitative population produced = 65.4 and s² = 2.8. Give the best point estimate for the population mean, . Calculate the margin of error.

Suppose a 95% confidence interval for the mean height of a 12-year-old male in the United States is 54 to 65 inches. In repeated sampling, 95% of the intervals constructed will contain the interval from 54 to 65 inches.

The wider the confidence interval, the more likely it is that the interval contains the true value of the population parameter.

A statistic is said to be unbiased if its sampling distribution has the smallest standard error.

A 90% confidence interval for the population mean is found to be between 5.28 and 6.72. Based on this information, the sample mean that generated the confidence interval was 6.

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

A 90% upper confidence bound (UCB) for the population proportion p can be constructed using the following equation: UCB =

The two limits that define an interval estimate are known as confidence limits.

A 90% confidence interval estimate for a population mean is determined to be 62.8 to 73.4. If the confidence level is reduced to 80%, the confidence interval for becomes narrower.

The margin of error is:

The concept of margin of error applies directly when estimating the population mean , but is not applicable when estimating the population proportion p.

Which of the following is a parameter?

In developing an interval estimate for a population mean, the population standard deviation was 8. The interval estimate was 40.52 3.24. Had equaled 16, the interval estimate would be:

Suppose that a 95% confidence interval for the population proportion p is given by . This notation means that we are 95% confident that p falls between and .

Those who engage in estimation insist on random sampling, rather than convenience sampling or judgment sampling, because random sampling:

For a given sample size and given confidence coefficient, the closer the population proportion p to 1.0, the greater the margin of error will be.

A random sample of n = 50 observations from a quantitative population produced = 65.4 and s2 = 2.8. Give the best point estimate for the population mean, . ______________ Calculate the margin of error. ______________

Suppose a 95% confidence interval for the mean height of a 12-year-old male in the United States is 54 to 65 inches. In repeated sampling, 95% of the intervals constructed will contain the interval from 54 to 65 inches.

The wider the confidence interval, the more likely it is that the interval contains the true value of the population parameter.

A statistic is said to be unbiased if its sampling distribution has the smallest standard error.

A 90% confidence interval for the population mean is found to be between 5.28 and 6.72. Based on this information, the sample mean that generated the confidence interval was 6.

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

A random sample of n = 50 observations from a quantitative population produced = 65.4 and s² = 2.8. Give the best point estimate for the population mean, . Calculate the margin of error.