Question 1

Find the 95% confidence interval for the variance of the heights of maple trees if a sample of 12 trees has a standard deviation of 10 feet.

Accepted Answer

A)  $11.0 < \sigma ^ { 2 } < 9.0$ 
B)  $7.0 < \sigma ^ { 2 } < 17.5$ 
C)  $89.0 < \sigma ^ { 2 } < 111.0$ 
D)  $48.8 < \sigma ^ { 2 } < 308.0$ 
A)  $11.0 < \sigma ^ { 2 } < 9.0$ 
B)  $7.0 < \sigma ^ { 2 } < 17.5$ 
C)  $89.0 < \sigma ^ { 2 } < 111.0$ 
D)  $48.8 < \sigma ^ { 2 } < 308.0$

Question 2

An interval estimate may or may not contain the value of the parameter being estimated.

Accepted Answer

A) True 
 B)False

Question 3

The area under each chi-square distribution is equal to __________. 
________________________________________

Accepted Answer

The answer of The area under each chi-square distribution is...

Question 4

What is the 95% confidence interval for the standard deviation of birth weights at Guelph General Hospital, if the standard deviation of the last 25 babies born there was 1.1 pounds?

Accepted Answer

A)  $08 < \sigma < 2.1$ 
B)  $0.7 < \sigma < 2.3$ 
C)  $08 < \sigma < 1.9$ 
D)  $09 < \sigma < 15$ 
A)  $08 < \sigma < 2.1$ 
B)  $0.7 < \sigma < 2.3$ 
C)  $08 < \sigma < 1.9$ 
D)  $09 < \sigma < 15$

Question 5

A sample of 23 European countries found that the variance on life expectancy was 7.3 years. What is the 95% confidence interval for the variance of life expectancy in Europe?

Accepted Answer

A)  $27.2 < \sigma ^ { 2 } < 118.3$ 
B)  $56 < \sigma ^ { 2 } < 10.3$ 
C)  $4.4 < \sigma ^ { 2 } < 14.6$ 
D)  $289 < \sigma ^ { 2 } < 1150$ 
A)  $27.2 < \sigma ^ { 2 } < 118.3$ 
B)  $56 < \sigma ^ { 2 } < 10.3$ 
C)  $4.4 < \sigma ^ { 2 } < 14.6$ 
D)  $289 < \sigma ^ { 2 } < 1150$

Question 6

Only the degree of confidence and the maximum error are necessary to determine the sample size if one
uses the "conservative" value for the standard error.

Accepted Answer

A) True 
 B)False

Question 7

The winning team's scores in 9 high school basketball games were recorded. If the sample mean is 10.5 points and the sample standard deviation is 0.15 points, find the 98% confidence interval of the

Accepted Answer

A)  (10.45, 10.55) 
B)  (10.36, 10.64) 
C)  (10.38, 10.62) 
D)  (10.21, 10.79) 
A)  (10.45, 10.55) 
B)  (10.36, 10.64) 
C)  (10.38, 10.62) 
D)  (10.21, 10.79)

Question 8

The width of a confidence interval for a population variance is of constant width for fixed values of the
sample size and confidence level.

Accepted Answer

A) True 
 B)False

Question 9

The Academy of Orthopedic Surgeons states that 80% of women wear shoes that are too small for their feet. A researcher wants to be 98% confident that this proportion is within 3% of the

Accepted Answer

A)  966 
B)  683 
C)  1183 
D)  484 
A)  966 
B)  683 
C)  1183 
D)  484

Question 10

The t-distribution must be used when the sample size is greater than 30 and the variable is normally or
approximately normally distributed.

Accepted Answer

A) True 
 B)False

Question 11

$\text { The term } z _ { \alpha / 2 } \left( \frac { \sigma } { \sqrt { n } } \right) \text { refers to the }$

Accepted Answer

A)  unbiased estimator. 
B)  confidence interval. 
C)  maximum error of estimate. 
D)  interval estimate. 
A)  unbiased estimator. 
B)  confidence interval. 
C)  maximum error of estimate. 
D)  interval estimate.

Question 12

A study of elephants wishes to determine the average weight of a certain subspecies of elephants. The standard deviation of the population is 2000 pounds. How many elephants need to be weighed so find we
Can be 80% confident to be accurate within 300 pounds?

Accepted Answer

A)  73 
B)  94 
C)  121 
D)  400 
A)  73 
B)  94 
C)  121 
D)  400

Question 13

A study of 60 white mice showed that their average weight was 5.7 ounces. The standard deviation of the population is 0.4 ounces. Which of the following is the 90% confidence interval for the mean weight per
White mouse?

Accepted Answer

A)  (5.62, 5.78) 
B)  (5.50, 5.90) 
C)  (5.60, 5.80) 
D)  (5.04, 6.36) 
A)  (5.62, 5.78) 
B)  (5.50, 5.90) 
C)  (5.60, 5.80) 
D)  (5.04, 6.36)

Question 14

What is the value for   for a 95% confidence interval when n = 18?

Accepted Answer

A)  7.564 
B)  7.289 
C)  6.547 
D)  8.312 
A)  7.564 
B)  7.289 
C)  6.547 
D)  8.312

Question 15

In a sample of 50 mice, a biologist found that 38% were able to run a maze in 30 seconds or less. Find the 95% limit for the population proportion of mice who can run that maze in 30 seconds or less.

Accepted Answer

A)  $31.3 \% < \mathrm { p } < 44.7 \%$ 
B)  $26.7 \% < \mathrm { p } < 49.3 \%$ 
C)  $24.5 \% < \mathrm { p } < 51.5 \%$ 
D)  $17.8 \% < \mathrm { p } < 58.2 \%$ 
A)  $31.3 \% < \mathrm { p } < 44.7 \%$ 
B)  $26.7 \% < \mathrm { p } < 49.3 \%$ 
C)  $24.5 \% < \mathrm { p } < 51.5 \%$ 
D)  $17.8 \% < \mathrm { p } < 58.2 \%$

Question 16

A previous analysis of paper boxes showed that the the standard deviation of their lengths is 7 millimeters. A pakcer wishes to find the 90% confidence interval for the average length of a box. How
Many boxes does he need to measure to be accurate within 3 millimeters?

Accepted Answer

A)  6 
B)  21 
C)  15 
D)  9 
A)  6 
B)  21 
C)  15 
D)  9

Find the 95% confidence interval for the variance of the heights of maple trees if a sample of 12 trees has a standard deviation of 10 feet.

An interval estimate may or may not contain the value of the parameter being estimated.

The area under each chi-square distribution is equal to . ______________________________

What is the 95% confidence interval for the standard deviation of birth weights at Guelph General Hospital, if the standard deviation of the last 25 babies born there was 1.1 pounds?

A sample of 23 European countries found that the variance on life expectancy was 7.3 years. What is the 95% confidence interval for the variance of life expectancy in Europe?

Only the degree of confidence and the maximum error are necessary to determine the sample size if one uses the "conservative" value for the standard error.

The winning team's scores in 9 high school basketball games were recorded. If the sample mean is 10.5 points and the sample standard deviation is 0.15 points, find the 98% confidence interval of the

The width of a confidence interval for a population variance is of constant width for fixed values of the sample size and confidence level.

The Academy of Orthopedic Surgeons states that 80% of women wear shoes that are too small for their feet. A researcher wants to be 98% confident that this proportion is within 3% of the

The t-distribution must be used when the sample size is greater than 30 and the variable is normally or approximately normally distributed.

$\text { The term } z _ { \alpha / 2 } \left( \frac { \sigma } { \sqrt { n } } \right) \text { refers to the }$

A study of elephants wishes to determine the average weight of a certain subspecies of elephants. The standard deviation of the population is 2000 pounds. How many elephants need to be weighed so find we Can be 80% confident to be accurate within 300 pounds?

A study of 60 white mice showed that their average weight was 5.7 ounces. The standard deviation of the population is 0.4 ounces. Which of the following is the 90% confidence interval for the mean weight per White mouse?

What is the value for for a 95% confidence interval when n = 18?

In a sample of 50 mice, a biologist found that 38% were able to run a maze in 30 seconds or less. Find the 95% limit for the population proportion of mice who can run that maze in 30 seconds or less.

A previous analysis of paper boxes showed that the the standard deviation of their lengths is 7 millimeters. A pakcer wishes to find the 90% confidence interval for the average length of a box. How Many boxes does he need to measure to be accurate within 3 millimeters?

The Nature of Probability and Statistics

Frequency Distributions and Graphs

Data Description

Discrete Probability Distributions

The Normal Distribution

Hypothesis Testing

Testing the Difference Between Two Means, Two Proportions, and Two Variances

Correlation and Regression

Chi-Square and Analysis of Variance Anova

Tables

Data Bank

Glossary

Filters

Exam 6: Confidence Intervals and Sample Size

Find the 95% confidence interval for the variance of the heights of maple trees if a sample of 12 trees has a standard deviation of 10 feet.

An interval estimate may or may not contain the value of the parameter being estimated.

The area under each chi-square distribution is equal to __________. ________________________________________

What is the 95% confidence interval for the standard deviation of birth weights at Guelph General Hospital, if the standard deviation of the last 25 babies born there was 1.1 pounds?

A sample of 23 European countries found that the variance on life expectancy was 7.3 years. What is the 95% confidence interval for the variance of life expectancy in Europe?

Only the degree of confidence and the maximum error are necessary to determine the sample size if one uses the "conservative" value for the standard error.

The winning team's scores in 9 high school basketball games were recorded. If the sample mean is 10.5 points and the sample standard deviation is 0.15 points, find the 98% confidence interval of the

The width of a confidence interval for a population variance is of constant width for fixed values of the sample size and confidence level.

The Academy of Orthopedic Surgeons states that 80% of women wear shoes that are too small for their feet. A researcher wants to be 98% confident that this proportion is within 3% of the

The t-distribution must be used when the sample size is greater than 30 and the variable is normally or approximately normally distributed.

The term zα/2(σn) refers to the \text { The term } z _ { \alpha / 2 } \left( \frac { \sigma } { \sqrt { n } } \right) \text { refers to the } The term zα/2​(n​σ​) refers to the

A study of elephants wishes to determine the average weight of a certain subspecies of elephants. The standard deviation of the population is 2000 pounds. How many elephants need to be weighed so find we Can be 80% confident to be accurate within 300 pounds?

A study of 60 white mice showed that their average weight was 5.7 ounces. The standard deviation of the population is 0.4 ounces. Which of the following is the 90% confidence interval for the mean weight per White mouse?

What is the value for for a 95% confidence interval when n = 18?

In a sample of 50 mice, a biologist found that 38% were able to run a maze in 30 seconds or less. Find the 95% limit for the population proportion of mice who can run that maze in 30 seconds or less.

A previous analysis of paper boxes showed that the the standard deviation of their lengths is 7 millimeters. A pakcer wishes to find the 90% confidence interval for the average length of a box. How Many boxes does he need to measure to be accurate within 3 millimeters?

The Nature of Probability and Statistics

Frequency Distributions and Graphs

Data Description

Discrete Probability Distributions

The Normal Distribution

Hypothesis Testing

Testing the Difference Between Two Means, Two Proportions, and Two Variances

Correlation and Regression

Chi-Square and Analysis of Variance Anova

Tables

Data Bank

Glossary

Filters

The area under each chi-square distribution is equal to . ______________________________

$\text { The term } z _ { \alpha / 2 } \left( \frac { \sigma } { \sqrt { n } } \right) \text { refers to the }$