Yikes! Not what we like to see, @Pm1955.
Did you run that speed test via WiFi? If so, please run one through an Ethernet/LAN cable to get the most accurate results for you connection.
Once you've done this, there are a few additional steps you can try:
Another suggestion would be to download the Optus@Home app, which guides you through testing your WiFi speed directly and modifying settings.
We have some extra information on improving your overall Broadband connection available here as well.