20. You have determined that your average collection time is 6.1 days. It takes your firm 4.5 days to prepare and mail out all the monthly statements to your customers who all pay promptly upon receipt. On average, the mail time between your firm and your customers is 2.4 days, and customer checks take an average of 1.8 days to clear the bank. How long, on average, is it taking your firm to process the payments from customers?