The probability density function of the weight of packages delivered by a post office is f(x) = 70/69x^2 for 1 < x < 70 pounds. a) Determine the mean and variance of weight. Round your answers to two decimal places (e. g. 98.76).b) If the shipping cost is $2.50 per pound, what is the average shipping cost of a package? Round your answer to two decimal places (e. g. 98.76).c) Determine the probability that the weight of a package exceeds 59 pounds. Round your answer to four decimal places (e. g. 98.7654).