can someone please help

1. [5 pts) 2:.) Consider a sample X1, .--1 X\" of normally distributed random variables with mean ,u and variance 02 = 13. (a) If n. = 24, what is the probability that |,u. XI 5 0.4? (b) What is this probability when n. = 48'? 2. (5 pts) Suppose that X1 and X2 are independent random variables. Suppose that E(X1) = p, Var[X1) = 5, E(X2) = ,u, and Var(X2) = 8. {a} What is the variance of r XI X2 H?+?. (b) What value of p minimizes the variance of all =PX1+[1'P)X2