Trusty Distribution has decided to analyze the profitability of five new customers. It buys bottled water at $12 per case and sells to retail customers at a list price of $15.00 per case. Data pertaining to the five customers are as follows: Compute the customer-level operating income of each of the five retail customers now being examined (P, Q, R, S, and T). Comment on the results. Begin by calculating each customer's gross margin Then calculate the operating income for each customer. (Complete all answer boxes. Use parentheses or a minus sign for operating losses.)