Assume the sediment density(g/cm) of randomly chosen specimen from certain region is normally distributed with the mean 2.65 and standard deviation .92.
a) If random sample of 25 specimens is chosen, determine the probability that the sample average sediment density is at most 3.00? Between 2.64 and 3.00?
b) How large a sample size would be required to ensure that the first probability in part (a) is at least .99?