Uh oh! Wolfram|Alpha doesn't run without JavaScript.
Please enable JavaScript. If you don't know how, you can find instructions
here
.
Once you've done that, refresh this page to start using Wolfram|Alpha.
n
*
Σ
x
y
-
Σ
x
*
Σ
y
n
*
Σ
x
2
-
Σ
x
2
Math Input
Natural Language
Math Input
