Question 15 4 pts Do bonds reduce the overall risk of an investment portfolio? Let x be a random variable representing annual percent return for the Vanguard Total Stock Index (all Stocks). Let y be a random variable representing annual return for the Vanguard Balanced Index (60o stock and 40%% bond). For the past several years, assume the following data. Compute war C 39 N 33 26 -4 N O 5599 5023 0 5311 O 4879