The cache is NOT at the posted coordinates.
You will need the Groundspeak (geocaching.com) Adventure Lab mobile app on your smartphone or tablet.
In order to get the final coordinates, you must complete the Adventure Lab, A Walk Around Logan's Tabernacle Square. It will require a data and/or a wi-fi connection.
The Lab app appears to have a bug where it sometimes does not display the final Journal entry when you answer the final question. Once you complete the lab you can view all the Journal entries. The coordinates to this cache will be in the last one.
Click here to get started.
Be aware that the parking lot next to the final location is not public. There is ample on-street parking nearby.