7.14 A pharmaceutical company claims to have developed a drug for simultaneously reducing blood vessel clogging cholesterol levels in the human body, and for inducing body weight reduction. To test this claim the Food and Drug Administration took a sample of 100 people and measured their cholesterol levels and body weights. A random half of the sample was given the new drug and the other half was given a placebo. After a suitable time cholesterol levels and body weights were recorded again. The data (in coded units) is as follows:

where denotes the average of the changes in the vector of cholesterol levels and body weights for the group that received the drug, and denotes the same quantity for the group that received the placebo; V1 and V2 denote the corresponding covariance matrices (unscaled). Assume bivariate normality with equal covariance matrices for the underlying data. Test the hypothesis that the drug has no effect, at the 5% level of significance.