Exam 12: Analysis of Variance

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 is $1,875. Using the 0.05 significance level, what is the decision regarding the null hypothesis?

Given the following Analysis of Variance table for three treatments each with six observations. What is the mean square for treatments?

The F distribution's curve is positively skewed.

The college of business was interested in comparing the interaction of Academic status and class time on class attendance. Three different classes were sampled for each cell in the table. The means for each cell follow. What are the total degrees of freedom?

Given the following Analysis of Variance table for three treatments each with six observations. What is the decision regarding the null hypothesis?

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 is $1,875. Using the 0.05 significance level, what is the F critical value for the hypothesis test?

When H₀ is rejected in ANOVA, _______ _______ are constructed to identify pairs of means that differ.

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: 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 -14.85 to 5.85 for the difference. This result indicates that