Answer:
Investor's before required rate of return is 12.5%
Step-by-step explanation:
The investor required return is the pretax return on the investment before applying the tax rate of 28%.
The pretax rate of return on the investment can be computed using the after tax return formula below by changing the subject of the formula to pretax rate of return;
After rate of return=pretax rate of return*(1-t)
t is the tax rate of 28% or 0.28
pretax rate of return is unknown
after tax rate of return is 9%
pretax rate of return=after tax rate of return/(1-t)
pretax rate of return=9%/(1-0.28)
pretax rate of return=9%/0.72
pretax rate of return =12.5%