True or false explain

A higher allocation to the risky portfolio increases the Sharpe ratio.

With a constant risk premium, a lower risk-free rate will increase the Sharpe ratio of investments that hold a portion of the risky portfolio

CAPM implies that investors require a higher rate of return to hold more volatile (higher standard deviation) securities.?

You can construct a portfolio with a beta of .75 by investing .25 of the investment in T-Bills and the remainder in the market portfolio.?