Problem $12-1$ Factor Models

A researcher has determined that a two$-$factor model is appropriate to determine the return on a stock. The factors are the percentage change in GNP and an interest rate. GNP is expected to grow by $4$ percent and the interest rate is expected to be $3\mathrm{.}5$ percent. A stock has a beta of $1\mathrm{.}7$ on the percentage change in GNP and a beta of $\mathrm{.}79$ on the interest rate. If the expected rate of return on the stock is $13$ percent, what is the revised expected return on the stock if GNP actually grows by $3\mathrm{.}6$ percent and the interest rate is $3\mathrm{.}8$ percent? $($Do not round intermediate calculations and enter your answer as a percent rounded to $2$ decimal places, e$.$g$.,32\mathrm{.}16.)$