Question 1

Calculate the 95% confidence interval for a sample with a mean   = 12.67 and a population standard error of the mean   = .98.

Accepted Answer

A)  95% CI = 12.67 ± 1.61 
B)  95% CI = 12.67 ± 1.92 
C)  95% CI = 12.67 ± 2.28 
D)  95% CI = 12.67 ± 2.52 
A)  95% CI = 12.67 ± 1.61 
B)  95% CI = 12.67 ± 1.92 
C)  95% CI = 12.67 ± 2.28 
D)  95% CI = 12.67 ± 2.52

Question 2

Calculate the 90% confidence interval for a sample of N = 17 with a mean   = 18.43 and standard error of the mean   = .72.

Accepted Answer

A)  90% CI = 18.43 ± 1.26 
B)  90% CI = 18.43 ± 2.10 
C)  90% CI = 18.43 ± 2.47 
D)  90% CI = 18.43 ± 1.53 
A)  90% CI = 18.43 ± 1.26 
B)  90% CI = 18.43 ± 2.10 
C)  90% CI = 18.43 ± 2.47 
D)  90% CI = 18.43 ± 1.53

Question 3

Calculate the lower and upper limits of the 95% confidence interval for a sample of N = 25 with a mean   = 10.50 and standard deviation (s) = 4.16.

Accepted Answer

A)  (8.83, 12.17) 
B)  (8.78, 12.22) 
C)  (8.17, 12.83) 
D)  (7.59, 13.41) 
A)  (8.83, 12.17) 
B)  (8.78, 12.22) 
C)  (8.17, 12.83) 
D)  (7.59, 13.41)

Question 4

Calculate the 95% confidence interval for a sample of N = 15 with a mean   = 3.50 and standard deviation (s) = .80.

Accepted Answer

A)  95% CI = 3.50 ± .45 
B)  95% CI = 3.50 ± .37 
C)  95% CI = 3.50 ± .63 
D)  95% CI = 3.50 ± 2.36 
A)  95% CI = 3.50 ± .45 
B)  95% CI = 3.50 ± .37 
C)  95% CI = 3.50 ± .63 
D)  95% CI = 3.50 ± 2.36

Question 5

If a researcher decreases the confidence level from 99% to 90%, the confidence interval for the mean is ______.

Accepted Answer

A)  widened 
B)  unchanged 
C)  narrowed 
D)  restricted 
A)  widened 
B)  unchanged 
C)  narrowed 
D)  restricted

Question 6

Use the formula   to calculate the 99% confidence interval for a sample of N = 15 with a mean   = 7.50 and standard error of the mean   = .32.

Accepted Answer

A)  99% CI = 7.50 ± .69 
B)  99% CI = 7.50 ± .56 
C)  99% CI = 7.50 ± .95 
D)  99% CI = 7.50 ± 3.30 
A)  99% CI = 7.50 ± .69 
B)  99% CI = 7.50 ± .56 
C)  99% CI = 7.50 ± .95 
D)  99% CI = 7.50 ± 3.30

Question 7

Calculate the lower and upper limits of the 95% confidence interval for a sample of N = 29 with a mean   = 52.49 and standard error of the mean   = 2.15.

Accepted Answer

A)  (48.29, 56.69) 
B)  (48.83, 56.15) 
C)  (46.55, 58.43) 
D)  (48.09, 56.89) 
A)  (48.29, 56.69) 
B)  (48.83, 56.15) 
C)  (46.55, 58.43) 
D)  (48.09, 56.89)

Question 8

Confidence limits are ______.

Accepted Answer

A)  a measure of variability 
B)  single values used to estimate an unknown population parameter 
C)  the lower and upper boundaries of a confidence interval 
D)  a range or interval of values that has a stated probability of containing an unknown population parameter 
A)  a measure of variability 
B)  single values used to estimate an unknown population parameter 
C)  the lower and upper boundaries of a confidence interval 
D)  a range or interval of values that has a stated probability of containing an unknown population parameter

Question 9

According to the author of the book, the flaws and weaknesses of hypothesis testing are NOT inherent to the statistical procedures themselves, but are rather a function of how researchers ______.

Accepted Answer

A)  estimate sample and population parameters 
B)  gather their data during the data collection process 
C)  input their data 
D)  use and interpret these procedures 
A)  estimate sample and population parameters 
B)  gather their data during the data collection process 
C)  input their data 
D)  use and interpret these procedures

Question 10

The confidence interval for the mean is ______.

Accepted Answer

A)  a range of values for a variable that has a stated probability of containing an unknown population mean 
B)  a single value used to estimate an unknown population parameter 
C)  the lower and upper boundaries of the confidence interval 
D)  a measure of variability 
A)  a range of values for a variable that has a stated probability of containing an unknown population mean 
B)  a single value used to estimate an unknown population parameter 
C)  the lower and upper boundaries of the confidence interval 
D)  a measure of variability

Question 11

The higher the desired level of confidence, the larger the confidence interval.

Accepted Answer

A) True 
 B)False

Question 12

Calculate the 95% confidence interval for a sample of N = 17 with a mean   = 12.42 and a population standard deviation (σ) = 5.00.

Accepted Answer

A)  95% CI = 12.42 ± 2.37 
B)  95% CI = 12.42 ± 2.00 
C)  95% CI = 12.42 ± 3.12 
D)  95% CI = 12.42 ± 3.17 
A)  95% CI = 12.42 ± 2.37 
B)  95% CI = 12.42 ± 2.00 
C)  95% CI = 12.42 ± 3.12 
D)  95% CI = 12.42 ± 3.17

Question 13

When a sample size is decreased, the confidence interval for the mean is then ______.

Accepted Answer

A)  narrowed 
B)  widened 
C)  more significant 
D)  less significant 
A)  narrowed 
B)  widened 
C)  more significant 
D)  less significant

Question 14

When a researcher increases the confidence level from 95% to 99%, the wider interval implies ______.

Accepted Answer

A)  increased precision in estimating the population mean 
B)  a lower confidence that the interval contains the population mean 
C)  a loss of precision in estimating the sample mean 
D)  decreased precision in estimating the population mean 
A)  increased precision in estimating the population mean 
B)  a lower confidence that the interval contains the population mean 
C)  a loss of precision in estimating the sample mean 
D)  decreased precision in estimating the population mean

Question 15

If a researcher chooses the 99% confidence interval instead of the 95% confidence interval, how does it affect the critical value of t?

Accepted Answer

A)  Critical value of t is lower. 
B)  Critical value of t is higher. 
C)  Critical value of t is unchanged. 
D)  Critical value of t is not dependent on the confidence interval chosen. 
A)  Critical value of t is lower. 
B)  Critical value of t is higher. 
C)  Critical value of t is unchanged. 
D)  Critical value of t is not dependent on the confidence interval chosen.

Question 16

What is the relationship between the size of a sample and the width of the confidence interval for the mean?

Accepted Answer

A)  The smaller the sample size, the narrower the confidence interval for the mean. 
B)  The larger the sample size, the narrower the confidence interval for the mean. 
C)  The larger the sample size, the wider the confidence interval for the mean. 
D)  The size of the sample has no influence on the width of the confidence interval for the mean. 
A)  The smaller the sample size, the narrower the confidence interval for the mean. 
B)  The larger the sample size, the narrower the confidence interval for the mean. 
C)  The larger the sample size, the wider the confidence interval for the mean. 
D)  The size of the sample has no influence on the width of the confidence interval for the mean.

Question 17

Calculate the lower and upper limits of the 90% confidence interval for a sample of N = 17 with a mean   = 18.43 and standard error of the mean   = .72.

Accepted Answer

A)  (17.17, 19.69) 
B)  (16.33, 20.53) 
C)  (15.96, 20.90) 
D)  16.90, 19.96) 
A)  (17.17, 19.69) 
B)  (16.33, 20.53) 
C)  (15.96, 20.90) 
D)  16.90, 19.96)

Question 18

Calculate the 99% confidence interval for a sample of N = 30 with a mean   = 1376.41 and standard error of the mean   = 30.73.

Accepted Answer

A)  99% CI = 1376.41 ± 62.84 
B)  99% CI = 1376.41 ± 52.15 
C)  99% CI = 1376.41 ± 84.81 
D)  99% CI = 1376.41 ± 33.48 
A)  99% CI = 1376.41 ± 62.84 
B)  99% CI = 1376.41 ± 52.15 
C)  99% CI = 1376.41 ± 84.81 
D)  99% CI = 1376.41 ± 33.48

Question 19

Calculate the lower and upper limits of the 95% confidence interval for a sample of N = 28 with a mean   = 16.39 and standard error of the mean   = .91.

Accepted Answer

A)  (14.52, 18.26) 
B)  (14.84, 17.94) 
C)  (13.87, 18.91) 
D)  (13.43, 19.35) 
A)  (14.52, 18.26) 
B)  (14.84, 17.94) 
C)  (13.87, 18.91) 
D)  (13.43, 19.35)

Question 20

Calculate the 99% confidence interval for a sample of N = 28 with a mean   = 13.64 and standard error of the mean   = 1.04.

Accepted Answer

A)  99% CI = 13.64 ± 2.13 
B)  99% CI = 13.64 ± 1.77 
C)  99% CI = 13.64 ± 2.88 
D)  99% CI = 13.64 ± 3.81 
A)  99% CI = 13.64 ± 2.13 
B)  99% CI = 13.64 ± 1.77 
C)  99% CI = 13.64 ± 2.88 
D)  99% CI = 13.64 ± 3.81

Calculate the 95% confidence interval for a sample with a mean = 12.67 and a population standard error of the mean = .98.

Calculate the 90% confidence interval for a sample of N = 17 with a mean = 18.43 and standard error of the mean = .72.

Calculate the lower and upper limits of the 95% confidence interval for a sample of N = 25 with a mean = 10.50 and standard deviation (s) = 4.16.

Calculate the 95% confidence interval for a sample of N = 15 with a mean = 3.50 and standard deviation (s) = .80.

If a researcher decreases the confidence level from 99% to 90%, the confidence interval for the mean is ______.

Use the formula to calculate the 99% confidence interval for a sample of N = 15 with a mean = 7.50 and standard error of the mean = .32.

Calculate the lower and upper limits of the 95% confidence interval for a sample of N = 29 with a mean = 52.49 and standard error of the mean = 2.15.

Confidence limits are ______.

According to the author of the book, the flaws and weaknesses of hypothesis testing are NOT inherent to the statistical procedures themselves, but are rather a function of how researchers ______.

The confidence interval for the mean is ______.

The higher the desired level of confidence, the larger the confidence interval.

Calculate the 95% confidence interval for a sample of N = 17 with a mean = 12.42 and a population standard deviation (σ) = 5.00.

When a sample size is decreased, the confidence interval for the mean is then ______.

When a researcher increases the confidence level from 95% to 99%, the wider interval implies ______.

If a researcher chooses the 99% confidence interval instead of the 95% confidence interval, how does it affect the critical value of t?

What is the relationship between the size of a sample and the width of the confidence interval for the mean?

Calculate the lower and upper limits of the 90% confidence interval for a sample of N = 17 with a mean = 18.43 and standard error of the mean = .72.

Calculate the 99% confidence interval for a sample of N = 30 with a mean = 1376.41 and standard error of the mean = 30.73.

Calculate the lower and upper limits of the 95% confidence interval for a sample of N = 28 with a mean = 16.39 and standard error of the mean = .91.

Calculate the 99% confidence interval for a sample of N = 28 with a mean = 13.64 and standard error of the mean = 1.04.

Introduction to Statistics

Examining Data: Tables and Figures

Measures of Central Tendency

Measures of Variability

Normal Distributions

Probability and Hypothesis Testing

Testing One Sample Mean

Testing the Difference Between Two Means

Errors in Hypothesis Testing, Statistical Power, and Effect Size

One-Way Analysis of Variance Anova

Two-Way Analysis of Variance Anova

Correlation

Linear Regression and Multiple Correlation

Chi-Square

Filters

Exam 8: Estimating the Mean of a Population

Calculate the 95% confidence interval for a sample with a mean = 12.67 and a population standard error of the mean = .98.

Calculate the 90% confidence interval for a sample of N = 17 with a mean = 18.43 and standard error of the mean = .72.

Calculate the lower and upper limits of the 95% confidence interval for a sample of N = 25 with a mean = 10.50 and standard deviation (s) = 4.16.

Calculate the 95% confidence interval for a sample of N = 15 with a mean = 3.50 and standard deviation (s) = .80.

If a researcher decreases the confidence level from 99% to 90%, the confidence interval for the mean is ______.

Use the formula to calculate the 99% confidence interval for a sample of N = 15 with a mean = 7.50 and standard error of the mean = .32.

Calculate the lower and upper limits of the 95% confidence interval for a sample of N = 29 with a mean = 52.49 and standard error of the mean = 2.15.

Confidence limits are ______.

According to the author of the book, the flaws and weaknesses of hypothesis testing are NOT inherent to the statistical procedures themselves, but are rather a function of how researchers ______.

The confidence interval for the mean is ______.

The higher the desired level of confidence, the larger the confidence interval.

Calculate the 95% confidence interval for a sample of N = 17 with a mean = 12.42 and a population standard deviation (σ) = 5.00.

When a sample size is decreased, the confidence interval for the mean is then ______.

When a researcher increases the confidence level from 95% to 99%, the wider interval implies ______.

If a researcher chooses the 99% confidence interval instead of the 95% confidence interval, how does it affect the critical value of t?

What is the relationship between the size of a sample and the width of the confidence interval for the mean?

Calculate the lower and upper limits of the 90% confidence interval for a sample of N = 17 with a mean = 18.43 and standard error of the mean = .72.

Calculate the 99% confidence interval for a sample of N = 30 with a mean = 1376.41 and standard error of the mean = 30.73.

Calculate the lower and upper limits of the 95% confidence interval for a sample of N = 28 with a mean = 16.39 and standard error of the mean = .91.

Calculate the 99% confidence interval for a sample of N = 28 with a mean = 13.64 and standard error of the mean = 1.04.

Introduction to Statistics

Examining Data: Tables and Figures

Measures of Central Tendency

Measures of Variability

Normal Distributions

Probability and Hypothesis Testing

Testing One Sample Mean

Testing the Difference Between Two Means

Errors in Hypothesis Testing, Statistical Power, and Effect Size

One-Way Analysis of Variance Anova

Two-Way Analysis of Variance Anova

Correlation

Linear Regression and Multiple Correlation

Chi-Square

Filters