- array_sum: documentation ( source)
- array_filter: documentation ( source)
<?php
$myArray = Array
(
0 => 1,
1 => 2,
2 => 0,
3 => 0,
4 => 0,
5 => "",
6 => 0,
7 => ""
);
echo array_sum($myArray) / count(array_filter($myArray));