Hi Megan,

You can create an automation. 
1. Add a formula field to the Project table to return the record id: RECORD_ID()
2. Add a rollup field to the Tasks table that rolls up the Record ID field from your projects table.  Use this aggregate formula:  CONCATENATE(values)
3.  Finally, create an automation to update your status field in the Projects table.  Use the "when the record matches conditions" trigger.   In your action, make sure you use your rollup field in the "Record ID" section:

If you want to talk about this further or if you ever need any more help, please schedule some time with me.  Here's my Calendly link: https://calendly.com/d/zgt-d2s-95m/15-minute-help-meeting

Jody

If the task is linked to the project, you could make an automation that triggers when that task type is checked off, and its action would be to update the project's checkbox field

You'll need to swap out the "Display as" portion so that it'll work:

If the task isn't linked to the project...well, I assume you've got some sort of identifier for each task that indicates which project it's for?  You could then use that in a "Find Records" action, followed by an "Update Record" action

It is linked! Thanks!