Question 989850
sum from -410 to 400: -1 - 2 ... -10 = -55


number of numbers: 400 - (-410) + 1 = 811


mean = -55/811


**My answer is correct. This questions for the mean of the INTEGERS FROM -410 to 400, not the integers -410 and 400 themselves.


-410 - 409 - 408 ... + 399 + 400 = (-400 - 399 ... - 1) + (1 + 2 + ... + 400) + (-10 - 9 - ... - 1)


The sum of the first 400 numbers cancel out, leaving only the sum from -1 to -10, which is -55.


You are right for the second part, however. I made a small calculation mistake. There are 811 numbers from -410 to 400, not 821. Next time, I would really appreciate your solution so I can understand my mistakes as well.