Chapter 7, Survey Sampling
Solution 5
I will tell me friend:
$$\tag*{$\blacksquare$} $$Dude, there are many things you get right but this is not one of them. When ${ \bar x } = 938.5$, it is a value which is for a particular sample of size 50. If we take another sample of size 50 - there is no guarantee that for that sample $\bar x$ will remain same.