Study of mutual fund performance. Refer to Exercise 9.92. Using an experimentwise error rate of .05, Tukey confidence intervals for the difference between mean rates of return for all possible pairs of fund types are given below.
a. Why is the Tukey multiple comparisons method preferred over another method?
b. Is there a significant difference between the treatment means for large-cap and medium-cap mutual funds? Explain.
c. Is there a significant difference between the treatment means for large-cap and small-cap mutual funds? Explain.
d. Is there a significant difference between the treatment means for medium-cap and small-cap mutual funds? Explain.
e. Use your answers to parts bâ€“d to rank the treatment means.
f. Give a measure of reliability for the inference in part e.
Study of mutual fund performance. Mutual funds are classified as large-cap funds, medium-cap funds, or small-cap funds, depending on the capitalization of the companies in the fund. Hawaii Pacific University researchers investigated whether the average performance of a mutual fund is related to capitalization size (American Business Review, January 2002). Independent random samples of 30 mutual funds were selected from each of the three fund groups, and the 90-day rate of return was determined for each fund. The data for the 90 funds were subjected to an analysis of variance, with the results shown in the ANOVA summary table below.
a. State the null and alternative hypotheses for the ANOVA.
b. Give the rejection region for the test using Â = .01.
c. Make the appropriate conclusion using either the test statistic or the p-value.