Read the box "The 'Beta' of a Stock".

a. Suppose the value of \(\beta\) is greater than 1 for a particular stock. Show that the variance of \(\left(R-R_{f}\right)\) for this stock is greater than the variance of \(\left(R_{m}-R_{t}\right)\).

b. Suppose the value of \(\beta\) is less than 1 for a particular stock. Is it possible that the variance of \(\left(R-R_{f}\right)\) for this stock is greater than the variance of \(\left(R_{m}-R_{t}\right)\) ? 

c. In a given year, the rate of return on 3 -month Treasury bills is \(2.0 \%\) and the rate of return on a large diversified portfolio of stocks (the S\&P 500) is \(5.3 \%\). For each company listed in the table in the box, use the estimated value of \(\beta\) to estimate the stock's expected rate of return.