I use mobile hotspot when i am in my room. Not much.. usually very quickly. Data? and I use Pandora while driving.. data?
There is no answer to your question. Every piece of data on the internet is different, you need to monitor your usage and understand what is going on through trial and error.
The best tool that is available is a Data Calculator:
Please note that the Data Calculator is an estimation tool and should not be depended or relyed on for real world results.
Depends free Pandora uses 128 kbps paid version uses 192 kbps. So a minimum of 56 MB per hour. So 1 hour per day would use 1.65 GB per month minimum. Paid version would use 50% more than that.