Question on averages, margin of error
The problem statement is: "Five shops were randomly chosen as a sample in 3 regions A,B and C.
The monthly profits are given as follows:
Shops Profit in millions
----- A B C
1 7 3 5
2 6 9 6
3 2 4 4
4 5 3 9
5 4 4 2
Examine whether the average profit per shop is the same for three regions?"
The average of the samples are:
Average of Samples for Region A: 4.8
Average of Samples for Region A: 4.6
Average of Samples for Region A: 5.2
However, I think based on above, we cannot immediately conclude that the average profits of all 3 regions are same or different, as I vaguely remember that average of samples will have an error of sigma/(sqrt(n), where 'n' is the sample size.
So I am stumped as to how to proceed further to solve this problem.