Solved just did not do it correctly need help

Exercise 1. Suppose that X is a random variable such that E(X) = 18.0 and E(X2) = 325.21". Define a new random variable by Y = 5X - 80. (A) Find the standard deviation ox for X. (Hint: It should be rational.) (B) Find E(Y). (C) Find the standard deviation oy for Y. 34 ox = X 4 ) E ( * # ) - E(x ) ? Ex2 - Ed 325. 21 - 18.02 Ox = VI. 6 = 1, 21 Ox = 1. B ) E ( 4 ) 4 = s (1.21 )- 80=1 -7 ( ) y = 50 ( 18 ) - 80 -3 * 4 = 7/10 Oy = y = / 3. 1 6 2 2