help with an equation

Question

Can someone help me with the question. I figured out how to do the bottom two but with the notes i have i am not sure how to do the first equation.

 

For the numbers 1,2,4,16 compute the following:

 

∑x

∑x=?

 

 

∑x²

 

∑x²= 1²+2²+4²+16² = 1+4+16+256 = 277

 

 

(∑x)²

 

(∑x)2 = 1+2+4+16=23

23²=529

Answer 1

It looks like just add the values of x; 1+2+4+16.