Stocks A and B have the following historical returns:

Year Stock A's Returns Stock B's Returns

2015 (24.25%) 5.50%

2016 18.50 26.73

2017 38.67 48.25

2018 14.33 (4.50)

2019 39.13 43.86

Average Rate of Return

Stock A: 17.28%

Stock B: 23.97%

Portfolio: 20.62%

a) Calculate the standard deviation of returns for each stock and for the portfolio.

b) Calculate the Sharpe Ratio for each stock and for the portfolio