I am trying to install a new app on my Mac Book and it is stuck on installing. It says it has installed 7.76 GB of 7.76 GB but it isn't doing anything else.

Yesterday I started installing an app from the app store onto my Mac Book. It is stuck on installing. It says it has installed 7.76GB of 7.76Gb and it won't do nothing else. It still shows it is doing something. I have tried to stop it, delete it, I did a shutdown of my computer and logged in and out of my apple account and nothing helps. It has ben like this for 16 hrs.