Question 1

Which of the following has an F distribution?

Accepted Answer

A) (n - 1)S/$\sigma$ 
B) S1/S2 
C) (n - 1)S1/S2 
D)     
A) (n - 1)S/$\sigma$ 
B) S1/S2 
C) (n - 1)S1/S2 
D)

Question 2

A lumber company has claimed that the standard deviation for the lengths of their 6 foot boards is 0.5 inches or less. To test their claim, a random sample of 17 six-foot boards is selected; and it is determined that the standard deviation of the sample is 0.4. Do the results of the sample support the company's claim? Use $\alpha$ = 0.1.

Accepted Answer

Since @#LAT-DLM&² = 25 > 23.54,

Question 3

At $\alpha$ = 0.1, test to see if the population variances from which the following samples were drawn are equal.

Accepted Answer

Since F = 1.26 < 2.1

Question 4

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 test statistic for this problem equals

Accepted Answer

A) 0.4132 
B) 1.96 
C) 2.42 
D) 1.645 
A) 0.4132 
B) 1.96 
C) 2.42 
D) 1.645

Question 5

The random variable for a chi-square distribution may assume

Accepted Answer

A) any value between -1 to 1 
B) any value between - infinity to +infinity 
C) any negative value 
D) any value greater than zero 
A) any value between -1 to 1 
B) any value between - infinity to +infinity 
C) any negative value 
D) any value greater than zero

Question 6

A sample of 20 cans of tomato juice showed a standard deviation of 0.4 ounces. A 95% confidence interval estimate of the variance for the population is

Accepted Answer

A) 0.2313 to 0.8533 
B) 0.2224 to 0.7924 
C) 0.3042 to 0.5843 
D) 0.0925 to 0.3413 
A) 0.2313 to 0.8533 
B) 0.2224 to 0.7924 
C) 0.3042 to 0.5843 
D) 0.0925 to 0.3413

Question 7

A sample of 51 elements is selected to estimate a 95% confidence interval for the variance of the population. The chi-square values to be used for this interval estimation are

Accepted Answer

A) -1.96 and 1.96 
B) 32.357 and 71.420 
C) 34.764 and 67.505 
D) 12.8786 and 46.9630 
A) -1.96 and 1.96 
B) 32.357 and 71.420 
C) 34.764 and 67.505 
D) 12.8786 and 46.9630

Question 8

The sampling distribution of the ratio of two independent sample variances taken from normal populations with equal variances is

Accepted Answer

A) an F distribution 
B) a chi-square distribution 
C) a t distribution 
D) a normal distribution 
A) an F distribution 
B) a chi-square distribution 
C) a t distribution 
D) a normal distribution

Question 9

We are interested in determining whether or not the variances of the sales at two small grocery stores are equal. A sample of 21 days of sales at Store A and a sample of 16 days of sales at Store B indicated the following.   
a.Provide the hypotheses to be tested.
b.Compute the test statistic.
c.Determine the critical value of F at 95% confidence.
d.Compute the p-value and use it to test the above hypotheses.

Accepted Answer

The answer of We are interested in determining whether or...

Question 10

We are interested in determining whether or not the variances of the sales at two small grocery stores are equal. A sample of 16 days of sales at each store indicated the following.   Are the variances of the populations (from which these samples came) equal?
Use $\alpha$ = 0.05.

Accepted Answer

The answer of We are interested in determining whether or...

Which of the following has an F distribution?

At $\alpha$ = 0.1, test to see if the population variances from which the following samples were drawn are equal. $At \alpha = 0.1, test to see if the population variances from which the following samples were drawn are equal.$

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 test statistic for this problem equals

The random variable for a chi-square distribution may assume

A sample of 20 cans of tomato juice showed a standard deviation of 0.4 ounces. A 95% confidence interval estimate of the variance for the population is

A sample of 51 elements is selected to estimate a 95% confidence interval for the variance of the population. The chi-square values to be used for this interval estimation are

The sampling distribution of the ratio of two independent sample variances taken from normal populations with equal variances is

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

Exam 11: Inferences About Population Variances

Which of the following has an F distribution?

At α\alphaα = 0.1, test to see if the population variances from which the following samples were drawn are equal.

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 test statistic for this problem equals

The random variable for a chi-square distribution may assume

A sample of 20 cans of tomato juice showed a standard deviation of 0.4 ounces. A 95% confidence interval estimate of the variance for the population is

A sample of 51 elements is selected to estimate a 95% confidence interval for the variance of the population. The chi-square values to be used for this interval estimation are

The sampling distribution of the ratio of two independent sample variances taken from normal populations with equal variances is

We are interested in determining whether or not the variances of the sales at two small grocery stores are equal. A sample of 16 days of sales at each store indicated the following. Are the variances of the populations (from which these samples came) equal? Use α\alphaα = 0.05.

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

At $\alpha$ = 0.1, test to see if the population variances from which the following samples were drawn are equal. $At \alpha = 0.1, test to see if the population variances from which the following samples were drawn are equal.$