作业帮标准方差题!(英文版)
来源：学生作业帮 编辑：作业帮 分类：英语作业 时间：2024/05/14 01:08:48
标准方差题!(英文版)
If a certain sample of data has a mean of 20 and a standard deviation of 3, which of the following values is more than 2.5 standard deviations from the mean?
A. 12.0
B. 13.5
C. 17.0
D. 23.5
E. 26.5
我根本就一点都不懂方差, 除了公式! 这句话什么意思? 怎么算?
谢谢!
If a certain sample of data has a mean of 20 and a standard deviation of 3, which of the following values is more than 2.5 standard deviations from the mean?
A. 12.0
B. 13.5
C. 17.0
D. 23.5
E. 26.5
我根本就一点都不懂方差, 除了公式! 这句话什么意思? 怎么算?
谢谢!
如果一组数据平均值为20,而标准方差为3,下面那个数值大于2.5倍标准方差范围?
首先先算出下面所有数值和平均值20的差别
A 8
B 6.5
C 3
D 3.5
E 6.5
2.5倍标准差也就是3×2.5=7.5只有A>7.5所以选A
首先先算出下面所有数值和平均值20的差别
A 8
B 6.5
C 3
D 3.5
E 6.5
2.5倍标准差也就是3×2.5=7.5只有A>7.5所以选A