$7.$ The Treasury bill rate is $5\%,$ the risk premium on the market portfolio is $7\%.$ Using CAPM answer the following questions.

$($a$)$ If the market expects a return of $15\%$ from a stock, what is its Beta? How can you interpret$/$explain this value? $(3$ points$)$

$($b$)$ What should be the expected return of an investment if it has a beta of $0\mathrm{.}8?$

$(3$ points$)$