Exam 12: Analysis of Variance

A random sample of 40 companies with assets over $10 million was selected and asked for their annual computer technology expense and industry. The ANOVA comparing the average computer technology expense among three industries rejected the null hypothesis. The Mean Square Error (MSE) was 195. The following table summarized the results: When comparing the mean annual computer technology expense for companies in the Education and Tax services industries, the following 95% confidence interval can be constructed:

For an ANOVA test, rejection of the null hypothesis does not identify which treatment means differ significantly.

When the null hypothesis for an ANOVA analysis comparing four treatment means, is rejected,

The F-distribution is useful when testing a requirement of two-sample tests of hypothesis. What is the assumption? ________________

What is the sum of squares divided by its corresponding degrees of freedom called? _________________

The alternative hypothesis used in ANOVA is .

To test the hypothesis that two population variances are equal, a random sample of size 13 was selected from the first population, and a random sample of size 21 was selected from the second population. Given that the sample standard deviation from the first population is larger than the sample standard deviation from the second population, what is the F-critical value using 0.01 as the significance level?

Given the following Analysis of Variance table for three treatments each with six observations. What is the critical value of F at the 5% level of significance?

In an one-way ANOVA, what are the degrees of freedom associated with the error sum of squares? ___________

What is the least number of sources of variation in ANOVA? _________

When a second source of variance is included in the ANOVA analysis without interaction, that source is called a _________________.

A random sample of 16 companies was selected and asked for their annual dividend rate in three different industries: utilities, banking, and insurance. The ANOVA comparing the mean annual dividend rate among three industries rejected the null hypothesis. The Mean Square Error (MSE) was 3.36. The following table summarized the results: Based on the comparison between the mean annual dividend rate for companies in the utilities and banking, the 95% confidence interval shows an interval of 1.28 to 6.28 for the difference. This result indicates that

Three different fertilizers were applied to a field of celery. In computing F, how many degrees of freedom are there in the numerator?

The college of business was interested in comparing the attendance for three different class times for a business statistics class. The data follow. What is the blocking variable?

A manufacturer of automobile transmissions uses two different processes. Management ordered a study of the production costs to see if there is a difference among the two processes. A summary of the findings is shown below. What is the critical value of F at the 5% level of significance?

A manufacturer of automobile transmissions uses three different processes. Management ordered a study of the production costs to see if there is a difference among the three processes. A summary of the findings is shown below. What are the degrees of freedom for the error sum of squares?

A random sample of 20 female executives from companies with assets over $1 million was selected and asked for their annual income and level of education. The ANOVA comparing the average income among three levels of education rejected the null hypothesis. The Mean Square Error (MSE) was 250. The following table summarized the results:

A bottle cap manufacturer with four machines and six operators wants to see if variation in production is due to the machines and/or the operators. ANOVA table follows. What is the critical value of F for the operator block effect at the 1% level of significance?

A manufacturer of automobile transmissions uses two different processes. Management ordered a study of the production costs to see if there is a difference between the two processes. A summary of the findings is shown below. What is the critical value of F at the 1% level of significance?

Suppose that an automobile manufacturer designed a radically new lightweight engine and wants to recommend the grade of gasoline that will have the best fuel economy. The four grades are: regular, below regular, premium, and super premium. The test car made three trial runs on the test track using each of the four grades and the miles per gallon recorded. At the 0.05 level, what is the critical value of F used to test the hypothesis that the miles per gallon for each fuel is the same?