Assume that a particular metropolitan area has a large number of primary care physicians and they operate in a competitive market, where the price of a physician visit is $100 per person. Each physician in this market can see up to 10 patients each day s/he works. The total cost of operation for a physician per day does not change regardless of how many patients s/he sees. Physicians make appointments with patients one week before they see them and decide whether to work for a particular day a week before. On average, they see 7 patients a day. However, they only work if at least 5 patients are scheduled for an appointment. Using the above information, what can you say about the daily variable cost of providing primary care services? (use a graph in the answer)