If x = 0, then y = 100, that is, the whole amount is invested risk-free. In this case the return is known with certainty to be KA = 0.1, that is, 10% and the risk as measured by the standard deviation is zero, σA = 0.
If x = 0, then y = 100, that is, the whole amount is invested risk-free. Inthis case the return is known with certainty to be KA = 0.1, that is, 10% and the risk as measured by the standard deviation is zero, σA = 0.