[CentOS] Shell Script Help

I have a script file in my cron.hourly that contains a good number of
scripts I must call.

#!/bin/sh

sleep 15
perl /scripts/create_graph.pl &

sleep 15
perl /scripts/create_graph_out.pl &

many more lines. etc.

Is there a way I can sleep random length to time before executing each
but background each one so master script returns promptly.  Something
like.

sleep (random 1 - 300 seconds, perl /scripts/create_graph_out.pl) &