Let x be a discrete random variable that takes on the values 2,3,4,5,6,7 with respective probabilities .10,.11,21.22,.23,.13. The following table summarizes this: a. Find the probability that x>0. b. Calculate the expected value ex of x c. Calculate the expected value exz of x2 d. Calculate the variance of x e. Calculate the standard deviation of x 1. Calculate the variance of 4X a nsuch unue R eorint in the box below