A botanist wishes to test the null hypothesis that the average diameter of the flowers of a particular plant is 9.6 cm. He decides to take a random sample of size n = 80 and accept the null hypothesis if the mean of the sample falls between 9.3 cm and 9.9 cm; if the mean of this sample falls outside this interval, he will reject the null hypothesis. What decision will he make and will it be in error if
(a) He gets a sample mean of 10.2 cm and µ = 9.6 cm;
(b) He gets a sample mean of 10.2 cm and µ = 9.8 cm;
(c) He gets a sample mean of 9.2 cm and µ = 9.6 cm;
(d) He gets a sample mean of 9.2 cm and µ = 9.8 cm?