I have two ways to calculate the average starting price of an auction item compared to it's actual value.
Starting Value Actual Value Percent
-------------- ------------ -------
1 2 50%
2 3 66%
3 4 75%
4 5 80%
5 6 83%
6 7 86%
7 8 88%
8 9 89%
9 10 90%
My question: which is the average starting price of the items as a percent?
SUM(start_values) / SUM(actual_values)
or
AVG(percent_value)
In this case, the difference is between 85% and 79%, which is sizable.
Which calculation will be most useful way to express the average starting price of all items, expressed as a percentage? We're having some debate here at work on the matter, and would like someone to set the record straight for us.