a) The expected return of Sheridan is 18.7 percent, and the expected return of Skysong is 23.7 percent. Their standard deviations are 12.7 percent and 20.7 percent, respectively. If a portfolio is composed of 40 percent Sheridan and the remainder Skysong, calculate the expected return and the standard deviation of the portfolio, given a correlation coefficient between Sheridan and Skysong of 0.35. (Round intermediate calculations to 4 decimal places, e.g. 31.2125 and final answers to 2 decimal places, e.g. 15.25%.)

b) Calculate the standard deviation if the correlation coefficient is 0.35. (Do not round intermediate calculations. Round answer to 2 decimal places, e.g. 15.25%.)