Do Bonds Reduce the Overall Risk of an Investment Portfolio $$\sum x ^ { 2 }$$

Multiple Choice

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. $$\sum x ^ { 2 }$$ $$\begin{array} { l l l l l l l l l l l } x : & 14 & 0 & 38 & 23 & 33 & 25 & 26 & - 14 & - 14 & - 23 \\y : & 9 & - 5 & 28 & 17 & 24 & 16 & 17 & - 5 & - 6 & - 9\end{array}$$

A) 5088
B) 4755
C) 4951
D) 5480
E) 4391