Exam 12: Analysis of Variance

When testing for differences between treatment means, the t statistic is based on ____________.

A random sample of 40 companies with assets over $10 million was surveyed and asked to indicate their industry and annual computer technology expense. 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: Based on the comparison between the mean annual computer technology expense for companies in the tax service and food service industries, the 95% confidence interval shows an interval of -5.85 to 14.85 for the difference. This result indicates that _______________.

In a one-way ANOVA, the degrees of freedom associated with the error sum of squares is __________.

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

Suppose a package delivery company purchased 14 trucks at the same time. Five trucks were purchased from manufacturer A, four from manufacturer B, and five from manufacturer C. The cost of maintaining each truck was recorded. The company used ANOVA to test if the mean maintenance costs of the trucks from each manufacturer were equal. To apply the F test, how many degrees of freedom must be in the denominator?

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 are the degrees of freedom for the denominator of the F ratio?

Analysis of variance is used to _____________.

Which statement is correct about the F distribution?

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: To compare the mean annual incomes of female executives with a high school education or less and female executives with a master's degree or more, compute the 90% confidence interval.

If the computed value of F is 0.99 and the F critical value is 3.89, we would not reject the null hypothesis.

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

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?

If an ANOVA test is conducted and the null hypothesis is rejected, what does this indicate?

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. To select a critical F-statistic, the number of degrees of freedom for the denominator is _____.

In a one-way ANOVA, ______ degrees of freedom are associated with the numerator of the F ratio.

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. Using the 0.05 significance level, what is the decision regarding the null hypothesis?

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?

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 alternate hypothesis?

All values in an F distribution must be _____________.

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 ___________.