After preparing the results of their measurement of the weight of children that participated in their pediatric study,St
After preparing the results of their measurement of the weight of children that participated in their pediatric study,Steph’s graduate assistant spilled coffee on their papers.If Steph is able to read that 50 lbs is the third standard deviation to the left of the mean,and 110 lbs also falls on a standard deviation,then which of the following could be the mean weight of the children in the study,assuming regular distribution?Indicate all possible values.
A80
B85
C86
D95
E100
题看不太懂
选A,C.D
因为80-50=30 30÷3=10 而110=80+3×10
86-50=36 36+3=12 而110=86+12×2
95-50=45 45÷3=15 而110=95+15×1
剩下两个除不尽.可是答案只有一个95 我不太懂题意你能解释下If Steph is able to read that 50 lbs is the third standard deviation to the left of the mean, and 110 lbs also falls on a standard deviation是什么意思吗如果Steph能够读出50磅是平均值向左的第三个标准差，而且110磅也落在标准差的点上
我的理解是这样的，设平均值为x，标准差为a
则x-3a=50，同时x+Na=110,其中满足N为整数，你看是不是这样。。但是答案为什么只有一个我没搞懂。。a standard deviation 会不会就是指的1个标准差啊？这样应该就是d选项了吧 对吗？看答案确实是这样的，但是题目中的“指出所有可能取值”。。。这一句又貌似在暗示不指一个答案，所以我也是没搞懂。。