<?php
$arr = Array
(
"chann_1" => 155.755,
"chann_2" => 154.61,
"chann_3" => 156.719,
"chann_4" => 156.727,
"chann_5" => 155.797,
"chann_6" => 157.615,
"chann_7" => 154.257,
"chann_8" => 151.724,
"chann_9" => 156.549,
"chann_10" => 156.594,
"chann_11" => 157.56,
"chann_12" => 156.405
);
Arsort($arr);
$keys = array_keys($arr);
Echo $keys[round(count($keys)/2)];
preferences:
29.24 ms | 402 KiB | 5 Q