Question

I’m dealing with some math problems here. We have the average sale and loss number in 3 stores.

Site     SALE     LOSS          % LOSS
-------------------------------------------
Store 1  474750   336740    70,92996314   (LOSS*100)/SALE
Store 2  321920   247810    76,97875249   
Store 3  149240   118440    79,36210131
-------------------------------------------
Total    945910   702990    74,31890983

If i sum the loss percentages of store 1,2 and 3 i get an average of 75.75.
But when i calculate the total SALE and LOSS and calculate the percentage LOSS i get 74.31?

Shouldent the numbers match? Or is this the wrong way?

Thank you for all answers!

Answer 1

You can’t average percentages when they’re taken from different totals. Calculating the total sale and loss is the correct way to do the calculation.

See Averaging Percentages on the Ask Dr. Math forum.