Produce an excel file to solve this question: >4. Suppose you form a portfolio that invests 10% in T, 20% in JPM, 30% in NEM and 40% in CVX. Calculate (a) portfolio returns for each month, (b) portfolio’s average monthly return, and (c) standard deviation of portfolio monthly returns. Discuss. Highlight your final answers. >4. Suppose you form a portfolio that invests 10% in T, 20% in JPM, 30% in NEM and 40% in CVX. Calculate (a) portfolio returns for each month, (b) portfolio’s average monthly return, and (c) standard deviation of portfolio monthly returns. Discuss. Highlight your final answers. See attached file for further instructions. Exercises 1 to 3 in it have been completed.