Could you please solve step by step in detail

7.11 A forester studying the effects of fertilization on certain pine forests in the Southeast is int- erested in estimating the average basal area of pine trees. In studying basal areas of similar trees for many years, he has discovered that these measurements (in square inches) are normally distributed with standard deviation approximately 4 square inches. If the forester samples n = 9 trees, find the probability that the sample mean will be within 2 square inches of the population mean. 7.11(b): Find the probability that the eighth observation in the sample (Y:) is within 2 square inches of the population mean (not the eighth largest or smallest, just the randomly picked eighth observation). 7.11(c): What happens to the probability of the sample mean being close to the population mean as we increase the sample size from 1 (as in (b)) to 9 (as in (a))