Problem 4: (12 Points) Download last 5 years monthly price data for AMZN and GM (May 2017 April 2022) and use adjusted close prices in your calculations. (You can get historical data from finance.yahoo.com) a) Calculate monthly returns for AMZN and GM. b) Calculate variance and standard deviation of monthly stock returns. c) Consider you have a portfolio with 20 shares of AMZN shares and 1000 shares of GM. For the last 5 years, calculate monthly portfolio return, then portfolio variance and standard deviation based on monthly portfolio returns. d) Get stock beta for AMZN and GM. Calculate expected returns of each stock. (Assume market return is 7% and use 1.25% as your risk-free rate)

PLEASE DO THE PROBLEM ON EXCEL AND SHOW THE FORMULA FOR EACH CELL.