# 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.

Kindly help.