Calculate the average monthly and average annual returns, and annual standard deviations for these stocks for the two subperiods of five years. (i.e. you should have one average monthly return and one average annual return for each 5-year period, because you will decompose the 10-year period into two subperiods of 5 years.)
Comment on these returns and standard deviations. What can you say about the actual returns you have in your data and the ones that are given in the table below?

  

Stock Amazon Southwest Airlines Johnson & Johnson Coca-Cola Beta (Pi) 1.47 1.35 0.81 0.70 Expected return rf + Bi (rm -rf) 12.3 11.5 7.7 6.9