giselle6790 giselle6790 30-05-2023 Business contestada Assume X~ N(-2,4). (a) Find the mean of 3(X + 1). (b) Find the standard deviation of X+4. (c) Find the variance of 2X-3. (d) Assume Y~ N(2, 2), and that X and Y are independent. Find the variance of X+Y.