You would like to combine a risky stock with a beta of 1.5 with U. S. Treasury bills in such a way that the risk level of the portfolio is equivalent to the risk level of the overall market. What percentage of the portfolio should be invested in Treasury bills

66.67 %

Explanation:

The computation of the percentage of the portfolio should be invested in Treasury bills is shown below:-

Let us assume beta be x

So the equation would be

Percentage of portfolio = x × (Beta of stock) + (1 - x) × (Beta of T - Bills) - 1

= x × (1.5) + (1 - x) × (Beta of T - Bills) - 1

1.5x + (1 - x) × (Beta of T - Bills) - 1

1.5x + 0 = 1

x = 1 ÷ 1.5

= 0.67

or

= 66.67%