A manufacturer claims that its wood treatment protects outdoor wood fences a mean of 2601 days with a standard deviation of 40.9 days. Assume a normal distribution. In a test of the claim, the wood treatment of a randomly selected fence lasted 2540 days.
(a) If the manufacturer's claim is true, what is the probability that the wood treatment on a randomly selected fence lasts a time less than 2540 days?
(b) Answer the question in (a) if the standard deviation is 25.1 days instead of 40.9 days.