The proportion of time per day that all checkout counters in a supermarket are busy is a random variable Ywith a density function given by f(y) = cy2(1 W5, 0 5 y 5 1: O, elsewhere. (a) Find the value of C that makes f(y) a probability density function. c = 0.01190 3 (b) Find E(Y). (Use what you have learned about the beta-type distribution.) Em=x (c) Calculate the standard deviation of Y. (Round your answer to four decimal places.) (d) Find P(Y > y + 20). (Round your answer to four decimal places.) S