precalc
posted by Alex on .
Use Sigma Notation to write the sum
[10(1/10)^2]+[10(2/10)^2]+[10(3/10)^2]+[10(4/10)^2]

Just look at the pattern. The only thing that changes is the denominator.
would it not be ..
4
∑ (10  i/10)^2
i=1
?