The following are the values of the weights of 20 packages of
butter produced in a processing plant: 4.01, 4.02, 4.oo, 4.09,
4.15, 4.07, 4.01, 3.95, 3.90, 3.99, 3.95, 4.01, 3.99, 4.08, 4.12,
4.20, 4.25, 4.21, 4.16, 4.o4.
(a) Test the hypothesis n ~ 4.o versus n > 4.o using the sign
test. Discard any value equal to 4.o. Carry out the test
at level of significance a = 0.0318.
(b) Test the hypotheses in part (a) using the Wilcoxon signed-rank
test at level of significance 0.05 (approximately).