Average of Averages

If we have two different data sets, say dataset 1 and dataset 2 with averages A1 and A2 respectively, and we are required to find their Combined Average, should we take the arithmetic mean of A1 and A2?

I have tested this. It works. But is there any exception to this?

If you require more explanation, please let me know.

No. You should take their weighted average instead. This depends on knowing how many elements are there in each of the datasets.

This is when the number of elements in the two datasets is the same.

Right. Thanks for the answer.