Cobie is evaluating her portfolio performances. She currently has two stock (stock BD and stock CL) in her portfolio which she acquired 6 months ago. She notices that the correlation coefficient of her portfolio are almost perfectly positive thus she is considering to remove stock -level List CL from her portfolio. Furthermore, stock CL is continuously having a drop in its value. The potential replacement is stock AM. Cobie downloaded the last five days' data of stock AM to help in her decision. Stock AM in RM) Open Close 1/7/2020 Date 2.20 2.50 2/7/2020 2.50 3.00 3/7/2020 3.00 4.20 4.20 3.78 4/7/2020 5/7/2020 3.78 5.67 She also observes that her current portfolio is having the following information: Date Rates of return (r) (in %) Stock BD Stock CL 1/7/2020 2/7/2020 10 -20 3/7/2020 5 -10 4/7/2020 20 5 5/7/2020 15 -5 Number of units owned 10,000 10,000 Given all the above information. a) Find the average return for stock AM. b) Find the standard deviation for stock AM. c) Find the covariance between stock AM and stock BD. d) Find the correlation coefficient between stock AM and stock BD. c) Based on your answer in d), should Cobie combine stock AM and BD in her portfolio? Explain your answer without calculation