Calculate the expected profit

In your 100-box simulation, the average box revenue was $131.36. Your shipped cost from the manufacturer was $87.50 per box. A game store agreed to post the cards online estimating 5% for the posting fee and 2% for shipping (7% total) in addition to the box cost. Lastly, the game store will take 50% of the profit for their service.

What is the net profit margin, for you, as defined below?

net profit = revenue - cost
profit margin = profit / revenue

You can use the console on the right as a calculator. The following operators will work: +, -, *, and /. Pressing enter will show you the results of your calculation.