Please see the attached Excel file. How did the Average Days in Part C (18, 55, 77, 97, 117) get solved? What was the formula? The excel file shows the formula for the final Average Collection Period of 43.14 days.

Original Question: Using these data, estimate the hospital's average collection period (ACP). (hint: Assume that the average age in the first category is 15 days, the midpoint of the range, the average age in the second category is 45 days, and so on. Ignore the receivable over 120 days.)