### Covariance and correlation between the returns on stocks

9.8 Using the returns for the period 1981 to 1985 listed below, calculate the five-year holding period return on the S&P 500 index. 1981 1982 1983 1984 1985 S&P 500 index return(%) -4.97 21.67 22.57 6.19 31.85 10.2. Suppose you have invested only in tw