回答数
5
浏览数
124
心如蝶舞
let's do listening comperhension.comperhension可能拼错了,你再查一下吧
无敌的小饭桶
Let's take the listening test .
candy00606
1/5[(男1-15)^2+(男2-15)^2+(男3-15)^2+(男4-15)^2+(男5-15)^2]=8那么[(男1-15)^2+……+(男5-15)^2]=A=40所以方差s^2=1/8*[A+(13-15)^2+(15-15)^2+(17-15)^2]=6
天棚元帅
8+(13-15)^2 +(15-15)^2+(17-15)^2=16
狮子猫的吃路
让我们来进行听力测试let's have a listening test
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