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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.

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    Both are things you can calculate. Neither is in and of itself more or less correct than the other. The pertinent question is not which of the calculations is "mathematically correct", but which calculation will be most _useful_ for whatever it is your eventual purpose is.2012-06-28
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    I'll edit the question.2012-06-28

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