Consider the fire-fighting foam expanding agents investigated in Exercise 10-18, in which five observations of each agent were recorded. Suppose that, if agent 1 produces a mean expansion that differs from the mean expansion of agent 1 by 1.5, we would like to reject the null hypothesis with probability at least 0.95.
(a) What sample size is required?
(b) Do you think that the original sample size in Exercise 10-18 was appropriate to detect this difference? Explain your answer.