# Can I get some help solving this problem? Thanks!

Mar 19, 2018

See below.

#### Explanation:

Calling ${S}_{n} = {\sum}_{k = 1}^{n} \left(a {k}^{2} + b k + c\right) = a \frac{n \left(n + 1\right) \left(2 n + 1\right)}{6} + b \frac{n \left(n + 1\right)}{2} + n c$

we need

${S}_{5}$

so you get the result making

$a = 0.17 , b = - 1.02 , c = 6.67 , n = 5$