#### Answer

$n$
$S_{4}=1^{2}+2^{2}+3^{2}+4^{2}=30$

#### Work Step by Step

The $n$th partial sum of a sequence is the sum of the first ___$n$___ terms of the sequence. So for the sequence $a_{n}=n^{2}$ the fourth partial sum is ___$S_{4}=1^{2}+2^{2}+3^{2}+4^{2}=30$___.