Answer:
45.95%
Step-by-step explanation:
If the security's correlation coefficient with the market portfolio doubles then beta, and t the risk premium will as well double.
The current risk premium is: 20% - 3% = 17%
Therefore the new risk premium would be 34% while the new discount rate for the security would be: 34% + 3% = 37%
Hence if the stock pays a constant perpetual dividend, then we know from the original data that the dividend (D) must satisfy the equation for the present value of a perpetuity:
Price = Dividend/Discount rate
43 = D/0.2 -> D
= 43 x 0.2 = $8.6
At the new discount rate of 37%, the stock would be worth: $8.6/0.37 = $23.24
$23.24/43 -1
=45.95%
Therefore the increase in stock risk has lowered its value by 45.95%.