suppose you have some money to invest-for simplicity,$1-and you are planning to put a fraction ω into a stock market mutual fund and the rest,1-ω,into a bond mutual fund. Suppose that $1 invested in a stock fund yields R¹after one year and that $1 invested in a bond fund yields R²,that R¹ is random with mean 0.08 and standard deviation 0.07, and that R² is random with mean 0.05 and standard deviation 0.04.The correlation between R¹ and R² is 0.25. if you place a fraction ω of your money in the stock fund and the rest,1-ω ,in the bond fund, then the return on your investment is R=ωR¹ +(1-ω )R². a.suppose that ω=0.5.compute the mean and standard deviation of R. 问题补充: 假设你有一笔钱投资 简单来说用$1表示 你把其中的一部分W资金投到stock market mutual fund 剩下的,1-ω投到 bond mutual fund。如果$1投入到stock fund 一年以后投资效益为R1,如果投入到bond fund 一年以后投资效益为R2,R1的随机变量的均值为0.08 标准差为0.07,R2的随机变量的均值为0.05 标准差为0.04.R1和R2的P为0.25 如果你把资金一部分ω 投入 stock fund 剩下,1-ω投入到 bond fund 而回报你的资金效益为R=ωR¹ +(1-ω )R²
