Question 1

The symbol used for the variance of the population is

Accepted Answer

A) $\sigma$ 
B) $\sigma$2 
C) S 
D) S2 
A) $\sigma$ 
B) $\sigma$2 
C) S 
D) S2

Question 2

Do the following data indicate that the variance of the population from which this sample has been drawn is significantly more than 17? Use $\alpha$ = 0.05.

Accepted Answer

Since @#LAT-DLM&² = 2.70 < 9.

Question 3

The standard deviation of the daily temperatures in Honolulu last year was 4 degrees Fahrenheit. A random sample of 25 days resulted in a standard deviation of 5.8 degrees Fahrenheit. Has there been a significant increase in the variance of the temperatures? Use $\alpha$ = 0.05.

Accepted Answer

Since @#LAT-DLM&² = 50.46 > 36

Question 4

We are interested in testing to see if the variance of a population is less than 7. The correct null hypothesis is

Accepted Answer

A) $\sigma$ 2 $\ge$ 7 
C) S  49 
A) $\sigma$ 2 $\ge$ 7 
C) S  49

Question 5

Exhibit 11-5  
-Refer to Exhibit 11-5. The test statistic for this problem equals

Accepted Answer

A) .63 
B) 12.68 
C) 13.33 
D) 13.66 
A) .63 
B) 12.68 
C) 13.33 
D) 13.66

Question 6

Exhibit 11-1
Last year, the standard deviation of the ages of the students at UA was 1.8 years. Recently, a sample of 61 students had a standard deviation of 2.1 years. We are interested in testing to see if there has been a significant change in the standard deviation of the ages of the students at UA.
-Refer to Exhibit 11-1. The p-value for this test is

Accepted Answer

A) 0.05 
B) between 0.025 and .05 
C) between .05 and .01 
D) 1.96 
A) 0.05 
B) between 0.025 and .05 
C) between .05 and .01 
D) 1.96

Question 7

The 90% confidence interval estimate for a population standard deviation when a sample variance of 50 is obtained from a sample of 15 items is

Accepted Answer

A) 4.18 to 15.07 
B) 5.18 to 11.15 
C) 5.44 to 10.32 
D) 29.55 to 106.53 
A) 4.18 to 15.07 
B) 5.18 to 11.15 
C) 5.44 to 10.32 
D) 29.55 to 106.53

Question 8

A sample of 61 observations yielded a sample standard deviation of 6. If we want to test Ho: $\sigma$2 = 40, the test statistic is

Accepted Answer

A) 54 
B) 9.15 
C) 54.90 
D) 9 
A) 54 
B) 9.15 
C) 54.90 
D) 9

Question 9

Exhibit 11-4  
-Refer to Exhibit 11-4. The p-value is between

Accepted Answer

A) 0.025 and 0.05 
B) 0.05 and 0.1 
C) 0.1 and 0.2 
D) 0.2 and 0.3 
A) 0.025 and 0.05 
B) 0.05 and 0.1 
C) 0.1 and 0.2 
D) 0.2 and 0.3

Question 10

We are interested in determining whether or not the variances of the starting salaries of accounting majors is significantly different from management majors. The following information was gathered from two samples.   At 90% confidence, test to determine whether or not the variances are equal.

Accepted Answer

H₀: variances are equal H_a: vari

Question 11

A sample of 60 items from population 1 has a sample variance of 8 while a sample of 40 items from population 2 has a sample variance of 10. If we test whether the variances of the two populations are equal, the test statistic will have a value of

Accepted Answer

A) 0.8 
B) 1.56 
C) 1.5 
D) 1.25 
A) 0.8 
B) 1.56 
C) 1.5 
D) 1.25

Question 12

Exhibit 11-4  
-Refer to Exhibit 11-4. At 95% confidence, the null hypothesis

Accepted Answer

A) should be rejected 
B) should not be rejected 
C) should be revised 
D) None of these alternatives is correct. 
A) should be rejected 
B) should not be rejected 
C) should be revised 
D) None of these alternatives is correct.

Question 13

A sample of 21 observations yielded a sample variance of 16. If we want to test H0: $\sigma$2 = 16, the test statistic is

Accepted Answer

A) 20 
B) 21 
C) 5 
D) 50 
A) 20 
B) 21 
C) 5 
D) 50

Question 14

Exhibit 11-7   We want to test the hypothesis that population A has a larger variance than population B.
-Refer to Exhibit 11-7. The p-value is approximately

Accepted Answer

A) 0.10 
B) 0.05 
C) 0.025 
D) 0.01 
A) 0.10 
B) 0.05 
C) 0.025 
D) 0.01

Question 15

The chi-square value for a one-tailed test (lower tail) when the level of significance is 0.1 and the sample size is 15 is

Accepted Answer

A) 21.064 
B) 23.685 
C) 7.785 
D) 6.571 
A) 21.064 
B) 23.685 
C) 7.785 
D) 6.571

Question 16

The 95% confidence interval estimate for a population variance when a sample variance of 324 is obtained from a sample of 81 items is

Accepted Answer

A) 14.14 to 174.94 
B) 243.087 to 453.518 
C) 16.42 to 194.35 
D) 15.591 to 21.296 
A) 14.14 to 174.94 
B) 243.087 to 453.518 
C) 16.42 to 194.35 
D) 15.591 to 21.296

Question 17

For an F distribution, the number of degrees of freedom for the numerator

Accepted Answer

A) must be larger than the number of degrees for the denominator 
B) must be smaller than the number of degrees of freedom for the denominator 
C) must be equal to the number of degrees of freedom for the denominator 
D) can be larger, smaller, or equal to the number of degrees of freedom for the denominator 
A) must be larger than the number of degrees for the denominator 
B) must be smaller than the number of degrees of freedom for the denominator 
C) must be equal to the number of degrees of freedom for the denominator 
D) can be larger, smaller, or equal to the number of degrees of freedom for the denominator

Question 18

The chi-square values (for interval estimation) for a sample size of 21 at 95% confidence are

Accepted Answer

A) 9.591 and 34.170 
B) 2.700 and 19.023 
C) 8.260 and 37.566 
D) -1.96 and 1.96 
A) 9.591 and 34.170 
B) 2.700 and 19.023 
C) 8.260 and 37.566 
D) -1.96 and 1.96

Question 19

To avoid the problem of not having access to Tables of F distribution with values given for the lower tail, the numerator of the test statistic should be the one with

Accepted Answer

A) the larger sample size 
B) the smaller sample size 
C) the larger sample variance 
D) the smaller sample variance 
A) the larger sample size 
B) the smaller sample size 
C) the larger sample variance 
D) the smaller sample variance

Question 20

A random sample of 20 observations showed a standard deviation of 8. At 95% confidence, test to see if the variance of the population is significantly less than 65. Use the critical value approach.

Accepted Answer

H₀: @#LAT-DLM&² @#LAT-DLM& 65 H_a: @#LAT-DLM&² < 65 chi

The symbol used for the variance of the population is

The standard deviation of the daily temperatures in Honolulu last year was 4 degrees Fahrenheit. A random sample of 25 days resulted in a standard deviation of 5.8 degrees Fahrenheit. Has there been a significant increase in the variance of the temperatures? Use $\alpha$ = 0.05.

We are interested in testing to see if the variance of a population is less than 7. The correct null hypothesis is

Exhibit 11-5 -Refer to Exhibit 11-5. The test statistic for this problem equals

The 90% confidence interval estimate for a population standard deviation when a sample variance of 50 is obtained from a sample of 15 items is

A sample of 61 observations yielded a sample standard deviation of 6. If we want to test H_o: $\sigma$ ² = 40, the test statistic is

Exhibit 11-4 -Refer to Exhibit 11-4. The p-value is between

We are interested in determining whether or not the variances of the starting salaries of accounting majors is significantly different from management majors. The following information was gathered from two samples. At 90% confidence, test to determine whether or not the variances are equal.

A sample of 60 items from population 1 has a sample variance of 8 while a sample of 40 items from population 2 has a sample variance of 10. If we test whether the variances of the two populations are equal, the test statistic will have a value of

Exhibit 11-4 -Refer to Exhibit 11-4. At 95% confidence, the null hypothesis

A sample of 21 observations yielded a sample variance of 16. If we want to test H₀: $\sigma$ ² = 16, the test statistic is

Exhibit 11-7 We want to test the hypothesis that population A has a larger variance than population B. -Refer to Exhibit 11-7. The p-value is approximately

The chi-square value for a one-tailed test (lower tail) when the level of significance is 0.1 and the sample size is 15 is

The 95% confidence interval estimate for a population variance when a sample variance of 324 is obtained from a sample of 81 items is

For an F distribution, the number of degrees of freedom for the numerator

The chi-square values (for interval estimation) for a sample size of 21 at 95% confidence are

To avoid the problem of not having access to Tables of F distribution with values given for the lower tail, the numerator of the test statistic should be the one with

A random sample of 20 observations showed a standard deviation of 8. At 95% confidence, test to see if the variance of the population is significantly less than 65. Use the critical value approach.

Data and Statistics

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Descriptive Statistics: Numerical Measures

Introduction to Probability

Discrete Probability Distributions

Continuous Probability Distributions

Sampling and Sampling Distributions

Interval Estimation

Hypothesis Tests

Inference About Means and Proportions With Two Populations

Comparing Multiple Proportions, Test of Independence and Goodness of Fit

Experimental Design and Analysis of Variance

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Nonparametric Methods

Statistical Methods for Quality Control

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Exam 11: Inferences About Population Variances

The symbol used for the variance of the population is

Do the following data indicate that the variance of the population from which this sample has been drawn is significantly more than 17? Use α\alphaα = 0.05.

The standard deviation of the daily temperatures in Honolulu last year was 4 degrees Fahrenheit. A random sample of 25 days resulted in a standard deviation of 5.8 degrees Fahrenheit. Has there been a significant increase in the variance of the temperatures? Use α\alphaα = 0.05.

We are interested in testing to see if the variance of a population is less than 7. The correct null hypothesis is

Exhibit 11-5 -Refer to Exhibit 11-5. The test statistic for this problem equals

The 90% confidence interval estimate for a population standard deviation when a sample variance of 50 is obtained from a sample of 15 items is

A sample of 61 observations yielded a sample standard deviation of 6. If we want to test Ho: σ\sigmaσ 2 = 40, the test statistic is

Exhibit 11-4 -Refer to Exhibit 11-4. The p-value is between

We are interested in determining whether or not the variances of the starting salaries of accounting majors is significantly different from management majors. The following information was gathered from two samples. At 90% confidence, test to determine whether or not the variances are equal.

A sample of 60 items from population 1 has a sample variance of 8 while a sample of 40 items from population 2 has a sample variance of 10. If we test whether the variances of the two populations are equal, the test statistic will have a value of

Exhibit 11-4 -Refer to Exhibit 11-4. At 95% confidence, the null hypothesis

A sample of 21 observations yielded a sample variance of 16. If we want to test H0: σ\sigmaσ 2 = 16, the test statistic is

Exhibit 11-7 We want to test the hypothesis that population A has a larger variance than population B. -Refer to Exhibit 11-7. The p-value is approximately

The chi-square value for a one-tailed test (lower tail) when the level of significance is 0.1 and the sample size is 15 is

The 95% confidence interval estimate for a population variance when a sample variance of 324 is obtained from a sample of 81 items is

For an F distribution, the number of degrees of freedom for the numerator

The chi-square values (for interval estimation) for a sample size of 21 at 95% confidence are

To avoid the problem of not having access to Tables of F distribution with values given for the lower tail, the numerator of the test statistic should be the one with

A random sample of 20 observations showed a standard deviation of 8. At 95% confidence, test to see if the variance of the population is significantly less than 65. Use the critical value approach.

Data and Statistics

Descriptive Statistics: Tabular and Graphical Displays

Descriptive Statistics: Numerical Measures

Introduction to Probability

Discrete Probability Distributions

Continuous Probability Distributions

Sampling and Sampling Distributions

Interval Estimation

Hypothesis Tests

Inference About Means and Proportions With Two Populations

Comparing Multiple Proportions, Test of Independence and Goodness of Fit

Experimental Design and Analysis of Variance

Simple Linear Regression

Multiple Regression

Regression Analysis: Model Building

Time Series Analysis and Forecasting

Nonparametric Methods

Statistical Methods for Quality Control

Index Numbers

Decision Analysis on Website

Sample Survey on Website

Filters

The standard deviation of the daily temperatures in Honolulu last year was 4 degrees Fahrenheit. A random sample of 25 days resulted in a standard deviation of 5.8 degrees Fahrenheit. Has there been a significant increase in the variance of the temperatures? Use $\alpha$ = 0.05.

A sample of 61 observations yielded a sample standard deviation of 6. If we want to test H_o: $\sigma$ ² = 40, the test statistic is

A sample of 21 observations yielded a sample variance of 16. If we want to test H₀: $\sigma$ ² = 16, the test statistic is