Suppose X has a standard normal distribution. The pnorm(), dnorm(), and qnorm() functions should be useful in the following. Remember, if X has a standard normal distribution then E(X) = 0 and Var(X)=1. a) What is the expected value of 0.5X-1+67 5.6667 3 b) What is the variance of 9.5X-1 -+6 7 .0278 3 X c) Using R, find the expected value of (x/2)?|0 d) Using R, calculate the probability X > -1.61) .9463 e) Using R, calculate the probability that -0.58