Final answer:
The beta of a portfolio that invests 50% in T-bills and the rest in a mutual fund indexed to match the market return would be 0.5.
Step-by-step explanation:
The beta of a portfolio is a measure of its sensitivity to market movements. The beta of an investment measures the investment's volatility relative to the overall market. The beta coefficient for T-bills is generally close to zero as they are considered to have low volatility. On the other hand, a mutual fund that is indexed to match the market return would typically have a beta close to 1 as it aims to replicate the market performance.
Since you are investing 50% of your money in T-bills and the rest in a mutual fund indexed to match the market's return, we can calculate the beta for the overall portfolio by taking a weighted average of the beta coefficients. In this case, it would be 0.5 times the beta of T-bills (approximately 0) plus 0.5 times the beta of the mutual fund (approximately 1), which gives us a total beta of 0.5.