



 
Alan, Suppose you are interested in what percentage of your sales are paid in cash. On day one you make 2 sales and both are for cash, so that's 100% of your sales on day one are for cash. On day two you make 10 sales and only 1 is for cash, so on day two 10% of your sales are for cash. Hence on the two days you made 12 sales and 3 were for cash so that's 25% cash sales over the two days. Averaging the 100% and 10% however gives 55%. It is not clear at all what this number represents. Harley  


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