applied statistics

5

5. Let X be a random variable with E(X) = 2 and var(X) = 9. Suppose I simulated X and got a value that was 2 standard deviations above what I would expect. What value of X did I simulate? (a) 2 (b ) 8 (C) 6 (d) 7 (e) 5 6. Let X , Y be two random variables with the following joint probability mass function. Find P(X + Y = 0). (a) 1/3 (b) 1 (c) 2/3 (d) 1/2 (6) 0