Answer:

Step-by-step explanation:
For this case we can construct the following table in order to find the mean for the grouped data:
Interval Frequency (fi) Midpoint (Xi) Xi *fi
5001-10000 27 7500.5 202513.5
10001-15000 23 12500.5 287511.5
15001-20000 12 17500.5 210006
20001-25000 18 22500.5 405009
25001-30000 30 27500.5 825015
Total 110 1930055
And the mean is calculated with the following formula:

Where 
So then if we replace into the formula we got:
