Can you please help me answer this question to this situation?

You are manager of a Restaurant that serves mostly seafood. The sales revenue of the restaurant has flattened in the last month. You are contemplating adding steaks, and other food items with beef and chicken to the menu.

What data you need to collect for a hypothesis test? How would you conduct a Goodness-of-Fit hypothesis test to make sure you would not make a costly mistake in your decision? Summarize the steps of the hypothesis test.