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 (60% stock and 40% bond). For the past several years, assume the following data. Compute . x: 14 0 36 24 35 26 27 -14 -14 -24 y: 8 -4 26 17 25 18 17 -4 -5 -8