【判断题】按照结构设计可以将轮胎分为斜交线轮胎、子午线轮胎。( )
【判断题】Internet是一个提供专门的网络服务的国际性组织。
【单选题】The standard error of the mean for a sample of 100 is 30. In order to cut the standard error of the mean to 15, we would
A.
increase the sample size to 200.
B.
increase the sample size to 400.
C.
decrease the sample size to 50.
D.
decrease the sample to 25.
【简答题】从用户角度看,Internet是一个( )
【判断题】In a sample of size 40, the sample mean is 15. In this case, the sum of all observations in the sample is ∑ Xi = 600.