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 arthmetic average return of company 's stock is (b)The anthmetic average retum of company Y:s stock is Requirement 2: (a) The historical variance of company X 's stock returns is: (Do not round intermediate calculations.) (b) The historical variance of company Y 's stock returns is: (Do not round intermediate calculations.) Requirement 3: (a) The historical standard deviation of company X's stock returns is: (Do not round intermediate calculations.) (b) The historical standard deviation of company Y's stock returns is: (Do not round intermediate calculations.)