Forecasting Methods
MathStat Grades
HW4homeworktemplate.xlsxP1
| Carpet City | |||||||
| Month | Demand for Soft Shag Carpet (1,000 yd.) | 3 mos moving average forecast | Weighted 3 mos moving average forecast | Error abs() | Error abs() | ||
| 1 | 10 | ||||||
| 2 | 9 | ||||||
| 3 | 8 | ||||||
| 4 | 9 | ||||||
| 5 | 10 | ||||||
| 6 | 12 | ||||||
| 7 | 14 | ||||||
| 8 | 11 | ||||||
| 9 | |||||||
| Please apply weights stated in the problem | Weights: 0.55 (most recent month), 0.35, 0.10 | ||||||
| Compute MAD on 3 mos moving average | Note: average over month 4 through 8 only. No data available to month 9 | ||||||
| Compute MAD on weighted 3 mos moving average | Note: average over month 4 through 8 only. No data available to month 9 | ||||||
| Which is a better forecast method? |
P2
| Petroco Service Station | ||||
| alpha = | 0.4 | |||
| Month | Gas Demand | Exp Forecast | Error | |
| October | 775 | ---- | ||
| November | 835 | |||
| December | 605 | |||
| January | 450 | |||
| February | 600 | |||
| March | 700 | |||
| April | 820 | |||
| May | 925 | |||
| June | 1500 | |||
| July | 1200 | |||
| August | ||||
| 8410 | SUM | |||
| MAPD | ||||
P3
| Science and Technology Mutual Fund | |||||||||
| alpha = | 0.3 | ||||||||
| Month | Fund Price | 3 mos moving average forecast | Weighted 3 mos moving average forecast | Exp Forecast | 3 mos MA error | Weighted 3 mos MA error | Exp. Smoothing error | ||
| 1 | 55 3/4 | ---- | ---- | ---- | |||||
| 2 | 54 1/4 | ---- | ---- | ||||||
| 3 | 55 1/8 | ---- | ---- | ||||||
| 4 | 58 1/8 | ||||||||
| 5 | 53 3/8 | ||||||||
| 6 | 51 1/8 | ||||||||
| 7 | 56 1/4 | ||||||||
| 8 | 59 5/8 | ||||||||
| 9 | 62 1/4 | ||||||||
| 10 | 59 1/4 | ||||||||
| 11 | 62 3/8 | ||||||||
| 12 | 58 | ||||||||
| 13 | 58 1/8 | ||||||||
| 14 | 62 3/4 | ||||||||
| 15 | 64 3/4 | ||||||||
| 16 | 66 1/8 | ||||||||
| 17 | 68 3/4 | ||||||||
| 18 | 60 1/2 | ||||||||
| 19 | 65 7/8 | ||||||||
| 20 | 72 1/4 | ||||||||
| 21 | |||||||||
| Please apply weights stated in the problem | Weight 0.5 (most recent), 0.3, 0.2 | ||||||||
| Compute MAD on 3 mos moving average | |||||||||
| Compute MAD on weighted 3 mos moving average | |||||||||
| Compute MAD on exponentially smoothed forecast | |||||||||
| Which is a better forecast method? |
P4
| Carpet City Regression | ||
| X - axis | Y - axis | |
| Monthly Construction Permits | Monthly Carpet Sales (1,000 yd.) | |
| 17 | 9 | |
| 25 | 14 | |
| 8 | 10 | |
| 7 | 12 | |
| 14 | 15 | |
| 7 | 9 | |
| 45 | 24 | |
| 19 | 21 | |
| 28 | 20 | |
| 28 | 29 | |
| Place regression output here | ||
| Y = A + Bx | ||
| A = | ||
| B = | ||
| Forecast Carpet sales for 30 construction permits | ||
| Correlation Coefficient |
P5
| Gilley's Ice Cream Parlor | |||
| x | y | ||
| Ave. Temp | Ice cream Sold | ||
| Week | (degrees) | (gal.) | |
| 1 | 68 | 80 | |
| 2 | 70 | 115 | |
| 3 | 73 | 91 | |
| 4 | 79 | 87 | |
| 5 | 77 | 110 | |
| 6 | 82 | 128 | |
| 7 | 85 | 164 | |
| 8 | 90 | 178 | |
| 9 | 85 | 144 | |
| 10 | 92 | 179 | |
| 11 | 90 | 144 | |
| 12 | 95 | 197 | |
| 13 | 80 | 144 | |
| 14 | 75 | 123 | |
| Place regression output here | |||
| (a) | Y = A + Bx | ||
| A = | |||
| B = | |||
| (b) | Correlation Coefficient | ||
| (c') | Coefficient of Determination | ||
| Explain the meaning of the coefficient of Determination below. What does it indicate? | |||
