How do I answer questions 5 and 6

5. Consider the following measurements of the heat producing capacity of the coal produced by two mines (in millions of calories per ton): Mine 1: 8260 8130 8350 8070 8340 Mine 2: 7950 7890 7900 8140 7920 7840 Assume that the populations are normal, can it be considered that the two population variances are equal? 6. Let X be a binomial random variable with parameters n and p. (a) Let U = X. Show that U is an unbiased estimator of p. (b) Let V = = X+n/2 Show that V is a biased estimator of p. 3n/2