问题如下：
What is the correlation between the two securities if the standard deviation of the portfolio is 27%?
选项：
A.-1
B.0
C.+1
解释：
C is correct.
We can use the method of exclusion to calculate when,
按照公式算，得到的结果是-1.111...
NO.PZ2018070201000043 问题如下 Whis the correlation between the two securities if the stanrviation of the portfolio is 27%? A.-1 B.0 C.+1 C is correct.We cuse the methoof exclusion to calculate when ρ=1, ω1σ1+ω2σ2=0.4*0.3+0.6*0.25=0.27 为什么不是用这个公式计算呀？
NO.PZ2018070201000043 问题如下 Whis the correlation between the two securities if the stanrviation of the portfolio is 27%? A.-1 B.0 C.+1 C is correct.We cuse the methoof exclusion to calculate when ρ=1, ω1σ1+ω2σ2=0.4*0.3+0.6*0.25=0.27 老师，我算出来的是这个？我这个哪里错了？请问解析那个是怎么退出来的
NO.PZ2018070201000043 问题如下 Whis the correlation between the two securities if the stanrviation of the portfolio is 27%? A.-1 B.0 C.+1 C is correct.We cuse the methoof exclusion to calculate when ρ=1, ω1σ1+ω2σ2=0.4*0.3+0.6*0.25=0.27 如上
NO.PZ2018070201000043 0 +1 C is correct. We cuse the methoof exclusion to calculate when ρ=1, ω1σ1+ω2σ2=0.4*0.3+0.6*0.25=0.27 我画框框的是我的计算过程，请老师详细给我讲解下哈
NO.PZ2018070201000043 就问组合标准等于%27什么条件都不给问correlation是多少？？？？？我什么都看不到0，4～0，3～这些数据答案解析里面的数据怎么来的？？？？？？
