1. Time Series Analysis and Forecasting
|
Week
|
Sales
|
Week
|
Sales
|
|
1
|
2750
|
7
|
3300
|
|
2
|
3100
|
8
|
3100
|
|
3
|
3250
|
9
|
2950
|
|
4
|
2800
|
10
|
3000
|
|
5
|
2900
|
11
|
3200
|
|
6
|
3050
|
12
|
3150
|
a. Construct a time series plot. What type of pattern exists in the data?
b. Use exponential smoothing with a = 0.4 to develop a forecast of demand for week 13. What is the resulting MSE?
2. 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.
a. Construct a time series plot. What type of pattern exists in the data?
b. Compare a three-month moving average forecast with an exponential smoothing fore¬cast for a = 0.2. Which provides the better forecasts using MSE as the measure of model accuracy?
c. What is the forecast for next month?
3. Corporate triple A bond interest rates for 12 consecutive months follow.
9.5 9.3 9.4 9.6 9.8 9.7 9.8 10.5 9.9 9.7 9.6 9.6
a. Construct a time series plot. What type of pattern exists in the data?
b. Develop three-month and four-month moving averages for this time series. Does the three-month or the four-month moving average provide the better forecasts based on MSE? Explain.