The table below shows historical annual returns for stocks of companies X and Y over recent years. Calculate the arithmetic average returns. In addition, calculate their historical variances, as well as their historical standard deviations. Requirement 1: (a)The arithmetic average return of company X 's stock is: (b)The arithmetic average return of company Y's stock is: Requirement 2: (a) The historical variance of company X 's stock returns is: (Do not round intermediate calculions.) (b) calculations.) Requirement 3: (a) ine historical standard deviation of company X's stock returns is: (Do not round (b) The historical standard deviation of company Y's stock returns is: (Do not round intermediate calculations.)