Answer
$\Sigma_{k=1}^{10}(\frac{4}{7})^k =1.3284$
Work Step by Step
$\Sigma_{k=1}^{10}(\frac{4}{7})^k =\frac{a(1-(r)^n)}{1-r}$
$a=(\frac{4}{7})^1=\frac{4}{7}$
$r=\frac{4}{7}$
$n= 10$
$\Sigma_{k=1}^{10}(\frac{4}{7})^k =\frac{(\frac{4}{7})(1-(\frac{4}{7})^{10})}{1-(\frac{4}{7})}=1.3284$