An investor has $$100,000$ to invest. If she invests $30\%$ in Stock $A,40\%$ in Stock $B,$ and the remainder in a market index

exchange$-$traded fund $($ETF$),$ calculate the investor's portfolio beta. The beta of Stock A is $0\mathrm{.}8$ while it is $1\mathrm{.}40$ for Stock $B.$

Hint:

A market index ETF should by definition have a beta of $1\mathrm{.}0$

a$.1\mathrm{.}10$

b$.0\mathrm{.}65$

c$.1\mathrm{.}00$

d$.2\mathrm{.}15$