5.1. Rice (1995, p. 390) gives the following data (Natrella, 1963) on the latent heat of the fusion of ice (cal/gm):

Method A: 79.98 80.04 80.02 80.04 80.03 80.03 80.04 79.97 80.05 80.03 80.02 80.00 80.02 Method B: 80.02 79.94 79.98 79.97 79.97 80.03 79.95 79.97

(a) Assuming normality, test the hypothesis of equal means, both with and without making the assumption of equal variances.

Compare the result with a WilcoxonIMann-Whitney nonparametric twosampIe test.

(b) Inspect the data graphically in various ways, for example, boxplots, Q-Q plots and histograms.

(c) Fit a one-way analysis of variance and compare it with your t-test. (Look ahead to the next chapter, or investigate function oneway.)