Chapter 11, Problem 54CE

Are large companies more profitable per dollar of assets? The largest 500 companies in the world were ranked according to their number of employees, with groups defined as follows: Small = Under 25,000 employees, Medium = 25,000 to 49.999 employees, Large = 50,000 to 99,000 employees, Huge = 100,000 employees or more. An ANOVA was performed using the company’s profit-to-assets ratio (percent) as the dependent variable. (a) What kind of ANOVA is this (one-factor, two-factor, etc.)? (b) What is your conclusion about the research question? Explain, referring either to the F test or p-value. (c) What can you learn from the plots that compare the groups? (d) Do you think the variances can be assumed equal? Explain your reasoning. (e) Perform Hartley’s test to test for unequal variances. (f) Which groups of companies have significantly different means? Explain.