#!/bin/bash
{ [ $# -ge 1 ] && [ $# -le 5 ]; } || {
echo "Must enter between 1 and 5 parameters"
exit 1
}

for P
do
echo $P >> /tmp/task3
done

echo "SORTED: $(sort -n -r /tmp/task3)"
rm -f /tmp/task3

Remove the quotes around the echo "SORTED:....." line - as long as you don't have whitespace in your passed parameters.

Cheers
ZB

thanks worked!