Assuming your arrays are both always the same length. You could use this:
$positions = array(0 => array(6.35,3.93), 1 => array(16.85,3.93), 2 => array(6.35,10.9), 3 => array(16.85,10.9), 4 => array(6.35,18.48), 5 => array(16.85,18.48), 6 => array(6.35,25.45), 7 => array(16.85,25.45));
$coupons = array ( 0 => 'NGP7xdaERK', 1 => 'LntKT38dXj', 2 => 'UBG2fplvnx', 3 => 'ymMkO6EF16', 4 => 'zsZCasRWrj', 5 => 'cl6UJ1a7VS', 6 => 'lrjc5vnpl6', 7 => 'mExuzQBOLs' ) ;
$result = array();
foreach($positions as $i=>$pos ) {
$result[$i] = array_merge($pos, (array)$coupons[$i]);
}
print_r($result);
Result:
Array
(
[0] => Array
(
[0] => 6.35
[1] => 3.93
[2] => NGP7xdaERK
)
[1] => Array
(
[0] => 16.85
[1] => 3.93
[2] => LntKT38dXj
)
[2] => Array
(
[0] => 6.35
[1] => 10.9
[2] => UBG2fplvnx
)
[3] => Array
(
[0] => 16.85
[1] => 10.9
[2] => ymMkO6EF16
)
[4] => Array
(
[0] => 6.35
[1] => 18.48
[2] => zsZCasRWrj
)
[5] => Array
(
[0] => 16.85
[1] => 18.48
[2] => cl6UJ1a7VS
)
[6] => Array
(
[0] => 6.35
[1] => 25.45
[2] => lrjc5vnpl6
)
[7] => Array
(
[0] => 16.85
[1] => 25.45
[2] => mExuzQBOLs
)
)