A forester studying the effects of fertilization on certain pineforests in the Southeast is interested in estimating the averagediameters of pine trees. In studying diameters of similar trees formany years, he has discovered that these measurements ( in inches )are normally distributed with mean 23 inches and standard deviation4 inches.
a) IF the forester samples n=16 trees, find the probability thatthe sample mean will be less than 26 inches.
b. Suppose the population mean is unknown, and the meandiameters of the selected 16 trees is 21.5 inches, construct a 94%confidence interval for the population mean.
c. How many trees must be measured in order to obtain a 98%confidence interval with a width equal to .3 inches.
