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So this is just part of my problem but its got me stumped for days and I cant ignore it since its popping up too often in my problems.

1. The problem statement, all variables and given/known data

For A sample of 140 bags of flour. The masses of x grams of the contents are summarized by [tex]\sum (x - 500) = -266[/tex] and [tex] \sum (x-500)^2=1178[/tex] I need to find the mean and estimated variance. The mean is simple 140(x - 500) = -266; mean = 498.3 But how the heck do I figure out [tex]\sum x^2[/tex] with the above info? I need only [tex]\sum x^2[/tex]

3. The attempt at a solution

Mostly I just doodled pages trying to get this one! =S I tried [tex]140(x - 500)^2 = 1178[/tex] And solve it, comes out as x = -1.780 or - 998.22. Which isn't correct. I need [tex]\sum x^2[/tex] basically in the formula for estimated variance [tex]s^2 = \frac{1}{n-1}(\sum x^2 - \frac{(\sum x)^2}{n})[/tex]

I tried reworking from the answer(variance=4.839) so sum of x2 should be 34773692.21 but I dont know how to get to this answer?

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# Homework Help: Figure out summation(x^2) in summation equation[Simple]

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