Exam 12: Analysis of Variance

Given the following ANOVA table for three treatments each with six observations: What is the decision regarding the null hypothesis?

When H₀: is rejected in ANOVA, we compute ____________ to identify pairs of means that differ.

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 next. What is the critical value of F at the 1% level of significance?

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. The ANOVA table follows.

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. The ANOVA table follows. What is the critical value of F for the operator block effect at the 1% level of significance? B.6 at the 0.01 significance level, with a 5 degrees of freedom numerator and a 15 degrees of freedom denominator.

If a confidence interval for the difference between a pair of treatment means includes 0, then we reject the null hypothesis that there is no difference in the pair of treatment means.

To employ ANOVA, the populations should have approximately equal standard deviations.

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 next. In an ANOVA table, what are the total degrees of freedom?

A company compared the variance of salaries for employees who have been employed for 5 years or less with employees who have been employed for 10 years or more. They randomly selected 21 employees with 5 years or less experience and 15 employees with 10 years or more experience. The standard deviation for the group with 5 years or less experience was $2,225; the standard deviation for the group with 10 years or more experience was $1,875. What is the F test statistic for the hypothesis test?

Two accounting professors decided to compare the variance of their grading procedures. To accomplish this, they each graded the same 10 exams, with the following results: At the 1% level of significance, what is the decision?

Two accounting professors decided to compare the variance of their grading procedures. To accomplish this, they each graded the same 10 exams, with the following results: What is the critical value of F at the 0.01 level of significance?

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. What are the degrees of freedom to test the hypothesis?

The null hypothesis for an ANOVA analysis comparing four treatment means is rejected. The four sample means are = 10, = 12, = 15, = 18. The sample size for each treatment is the same. If ( - ) is significantly different from zero, then ___________.

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. The ANOVA table follows. What is the computed value of F for the machines?

A large department store examined a sample of the 18 credit card sales and recorded the amounts charged for each of three types of credit cards: MasterCard, Visa, and Discover. Six MasterCard sales, seven Visa, and five Discover sales were recorded. The store used an ANOVA to test if the mean sales for each credit card were equal. What are the degrees of freedom for the F statistic?

Two accounting professors decided to compare the variance of their grading procedures. To accomplish this, they each graded the same 10 exams, with the following results: The calculated F ratio is ______.

What distribution does the F distribution approach as the sample size increases?

The annual dividend rates for a random sample of 16 companies in three different industries, utilities, banking, and insurance were recorded. The ANOVA comparing the mean annual dividend rate among three industries rejected the null hypothesis that the dividend rates were equal. The mean square error (MSE) was 3.36. The following table summarized the results: When comparing the mean annual dividend rate for companies in the utilities and insurance industries, which of the following 95% confidence interval can be constructed?

In a study of protein breakfast bars, five bars from each of three brands were tested to see if the mean amount of protein per bar differs among the brands. The F critical value for α = 0.05 is _____.

ANOVA is a statistical approach used to determine whether or not _________.