Expert: Ahmed Salami - 8/27/2004

Question
Hi Ahmed. I'm stuck with the following average question. I'd appreciate your help...
Regards,

Celine

Question:
The average of P numbers is X, and the average of N numbers is Y. What is the average of all the (P + N) numbers?

Answer
Hi Celine,
The sum of the P numbers would be PX while that of the N numbers would be NY. Altogether, there are now P + N numbers and their sum is PX + NY .
So the average of the P + N numbers is
(PX + NY)/(P + N)

I hope you understand it.
Good luck.
Regards.