An investment has possible rates of return of 7%, 10%, and 15% over five years. The probabilities of attaining these rates, estimated on the basis of the current economy, are 0.65, 0.25, and 0.1, respectively. If you have ¥10 000 to invest,
(a) Vvnat is the expected rate of return from this investment?
(b) Wha t is the variance of the rate of return on this investment?