1. Write a formula below which references to calculate the average number of firm interactions per customer based on all of the available data.

For the remaining questions in this section, use the following values, which show the sales from three stores over three months. When answering each question, enter the calculation that uses the appropriate Excel formula. 50 100 20 110 200 20 120 200 150 200 30 Sales ($k) Store Month B C C A January C C January A February | February A March 30 A April B March | April January February March April