MATHEMATICS
posted by DAN .
How do you find the average deviation from these numbers:
290 , 270 , 250 , 300 , & 290.
I think their mean is 280

average deviation would be the average of the deviations from the mean.
If the mean is 280, then the deviations are
10 10 30 20 10
figure the average of those numbers. 
how did u get those numbers?

The deviation is the difference between a value and the mean.
So the deviations are:
(290280) (270280) (250280) (300280) (290280)
This gives you: 10 10 30 20 10
The average is the sum of the numbers divided by the number of numbers (5).
so that would be 0/5 = 0.