Consider the following five monthly returns: a. Calculate the arithmetic average monthly return over this period. b. Calculate the geometric average monthly return over this period. c. Calculate the monthly variance over this period. d. Calculate the monthly standard deviation over this period. a. Calculate the arithmetic average monthly return over this period. The arithmetic average is \%. (Round to two decimal places.) The 95\% prediction interval of the S8P500 is between \& and \%. (Round to two decimal places and put the lower number first)