please explain the steps thanks

2. Ph oenix Company common stock is currently selling for $20 per share. Security analysts at Smith arney have assigned the following probability distribution to the price of (and rate of return on) Phoenix stock one year from now: Price $16 20 2 4 28 Probability 0.25 0.30 0.25 0.20 Rate of Return -20% 08 +20% +40% Assuming that Phoenix is not expected to pay any dividends during the coming year, determine the tandard deviation of possible rates of return on Phoenix stock (to the nearest tenth of a percent). a. 45690 b. 20.990 c. 2.2% d. 21.4%