问题已解决
老师,我怎么计算的不一样啊,算了好几次
![](https://member.chinaacc.com/homes/resources/images/home/avatar/0.jpg)
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![](https://pic1.acc5.cn/011/72/76/90_avatar_middle.jpg?t=1714278024)
您好
A股票收益率的标准差=[0.3×(20%一8.5%)^2+0.4×(10%―8.5%)^2+0.3×(―5%―8.5%)^2]½=(0.0039675+0.00009+0.0054675)^1/2=9.76%
B股票收益率的标准差=[0.3×(30%一14.5%)^2+0.4×(10%-14.5%)^2+0.3×(5%-14.5%)^2]^1/2=(0.0072075+0.00081+0.0027075)^1/2=10.36%
2021 08/26 19:52
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84784970 ![](/wenda/_nuxt/img/reply1.d92ea43.png)
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2021 08/26 20:04
负数那算错了,谢谢老师
![](http://member.chinaacc.com/homes/resources/images/home/avatar/0.jpg)
84784970 ![](/wenda/_nuxt/img/reply1.d92ea43.png)
![](/wenda/_nuxt/img/reply1.d92ea43.png)
2021 08/26 20:11
老师,考试计算器上有开方吗
![](https://pic1.acc5.cn/011/72/76/90_avatar_middle.jpg?t=1714278024)
朱小慧老师 ![](/wenda/_nuxt/img/reply2.28c7604.png)
![](/wenda/_nuxt/img/reply2.28c7604.png)
2021 08/26 20:14
有开平方的,就是开根号的那个键
![](http://member.chinaacc.com/homes/resources/images/home/avatar/0.jpg)
84784970 ![](/wenda/_nuxt/img/reply1.d92ea43.png)
![](/wenda/_nuxt/img/reply1.d92ea43.png)
2021 08/26 20:15
好的,谢谢
![](https://pic1.acc5.cn/011/72/76/90_avatar_middle.jpg?t=1714278024)
朱小慧老师 ![](/wenda/_nuxt/img/reply2.28c7604.png)
![](/wenda/_nuxt/img/reply2.28c7604.png)
2021 08/26 20:15
好的,不客气,难道对我的回复进行评价,谢谢