The heights of fully grown oak trees in a certain county are normally distributed. Random samples of four trees are selected. The mean and standard deviation of the sampling distribution are 90 feet and 1.75 feet respectively. Do not write units when answering the questions below.

(a) =feet

(b) =feet

(c) Using the answers in parts (a) and (b), find the probability, to the nearest hundredth, that the height of a fully grown oak tree in the county is at least 95 feet.

(d) Using the answers in parts (a) and (b), find the probability, to the nearest hundredth, that the height of a fully grown oak tree in the county is between 80 and 95 feet.