please help me solve for b, the investments standard deciation. TY!

(Related to Checkpoint 7.1) (Expected rate of return and risk) B. J. Gautney Enterprises is evaluating a security. One-year Treasury bills are currently paying 2.9 percent. Calculate the investment's expected return and its standard deviation. Should Gautney invest in this security? a. The investment's expected return is 6. (Round to two decimal places.) b. The investment's standard deviation is \%. (Round to two decimal places.)