You have invested in a portfolio of AMZN stock and Tbills. The AMZN stock has an expected return of 16 percent, and the Tbill has a rate of return of 4 percent. Your portfolio has an expected return of 12:4 percent. What is the portfolio weight of the AMZN stock? (Hint: Write the weight of AMZN as w. Then the weight of the Tbill is 1 w: You should solve for w.)

(a) 0:30

(b) 0:40

(c) 0:60

(d) 0:70