Question 15 S = X1+ X2 + X3 + X4 Each of the X random variables (independent and identical ) are Geometric with p= 1/2. What is mean of S What is the standard deviation of S (rounded 2 decimal places) (0.**) {S 13}. It means 4th head occurs on 13th trial and 3 heads and 9 tails occur in the first 12 trials. I have done it in class Find p1= P(A) exact = Rounded to 4 decimal places entered as 0.**** Find p2 = Bell curve estimate of p1 with CF. Rounded to 4 decimal places entered as 0.**** 100(p2-pl) Compute r = rounded to nearest whole number.