Using the following returns, calculate the arithmetic average returns, the variances, and the standard deviations for X and Y. Returns Year X Y 1 10 % 18 % 2 28 39 3 17 -7 4 -18 -21 5 19 47 Requirement 1: (a) Calculate the arithmetic average return for X. (b) Calculate the arithmetic average return for Y. Requirement 2: (a) Calculate the variance for X. (Do not round intermediate calculations.) (b) Calculate the variance for Y. (Do not round intermediate calculations.) Requirement 3: (a) Calculate the standard deviation for X. (Do not round intermediate calculations.) (b) Calculate the standard deviation for Y. (Do not round intermediate calculations.)