a. Reconsider the patient arrival data in Example 8.3. It is now the end of week 3, so the actual number ofarrivals is known to be 411 patients. Using a = 0.10, calculate the exponential smoothing forecast forweek 4.b. What was the forecast error for week 4 if the actual demand turned out to be 415?c. What is the forecast for week 5?