# How do I use summation notation to write the series 2.2 + 6.6 + 11?

Sep 15, 2015

${\sum}_{n = 0}^{2} \left(2.2 + 4.4 n\right)$

#### Explanation:

Perhaps the biggest problem here is to recognize the arithmetic progression of the given values:

$2.2$

$6.6 = 2.2 + 4.4$

$11 = 6.6 + 4.4$
$\textcolor{w h i t e}{\text{X}} = 2.2 + 4.4 + 4.4$

So starting with a base value of $2.2$ each step increases by $4.4$