Expected rates of return for the market and stock

Question

Problem: The market and Stock J have tire following probability distributions:

Expected Returns

Probability    rM,         rl
0.3               15%     20%
0.4                9          5
0.3               18        12

Q1. Calculate the expected rates of return for the market and Stock J.

Q2. Calculate the standard deviations for the marker and Stock J.

Q3. Calculate he coefficients of variation for the markdt and Stock J.