Suppose Intel stock has a beta of $0\mathrm{.}89,$ whereas Boeing stock has a beta of $1\mathrm{.}28.$ If the risk$-$free interest rate is $5\mathrm{.}7\%$ and the expected return of the market portfolio is $11\mathrm{.}5\%,$ according to the CAPM

a$.$ What is the expected return of Intel stock?

b$.$ What is the expected return of Boeing stock?

c$.$ What is the beta of a portfolio that consists of $55\%$ Intel stock and $45\%$ Boeing stock?

d$.$ What is the expected return of a portfolio that consists of $55\%$ Intel stock and $45\%$ Boeing stock? $($There are two ways to solve this.$)$