Chapter 8, Problem 11P

For the Hawkins Company, the monthly percentages of all shipments received on time over the past 12 months are 80, 82, 84, 83, 83, 84, 85, 84, 82, 83, 84, and 83.

1. a. Construct a time series plot. What type of pattern exists in the data?
2. b. Compare a three-month moving average forecast with an exponential smoothing forecast for α = 0.2. Which provides the better forecasts using MSE as the measure of model accuracy?
3. c. What is the forecast for next month?