Why we use T statistice?
Why don't you use z-statistics?
Aren't all sales in 2016 not in the US?
If we want to think about the scale of 2016 for the United States, I think we should use ZStatistics because we have all the sales for 2016 in the United States.
1 answers ( 0 marked as helpful)
Because it's a sample of 30 years of sales