Chapter 15.1, Problem 2E

Here again is the data on expense ratio (%) for a sample of 20 large-cap blended mutual funds introduced in Exercise 1.53:

A normal probability plot show's a distinctly nonlinear pattern, primarily because of the single outlier on each end of the data. But a dotplot and boxplot exhibit a reasonable amount of symmetry. Assuming a symmetric population distribution, does the data provide compelling evidence for concluding that the population mean expense ratio exceeds 1%? Use the Wilcoxon test at significance level .1. [Note: The mean expense ratio for the population of all 825 such funds is actually 1.08.]