Calculate expected rates of return for market and stock

Question

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

Probability    rm    rj
0.3             15%    20%
0.4              9         5
0.3             18       12

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

B. Calculate the standard deviations for the market and Stock J.

C. Calculate the coefficient of variation for the market and Stock J.