Question 784988
Q:
Find the mean of the integers from -410 to 400. Explain how you got your answer. 
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A:
sum of the numbers 
= [(-1 + 1) + (-2 + 2) + (-3 + 3) + ... + (-400 + 400)] + (-401) + (-402) + ... + (-410)
= [0 + 0 + 0 + ... + 0] + (-4055)
= -4055

There are 410 negative integers, 400 positive integers, and a zero.
There are 410 + 400 + 1 = 811 integers in all.

mean (average) = -4055/811 = {{{highlight(-5)}}}