In: Statistics and Probability
Exercise
| 1. Graph three plots Sales, Forecast, center moving average | ||||
| 2. Predict the sales in year 5 for each quarter using forecasting | ||||
| Quarter Data for Car Sales | ||||
| Year | Quarter | Sales (1000's) | Moving average (4) | Center moving average (baseline) |
| year 1 | 1 | 4.8 | ||
| 2 | 4.1 | |||
| 3 | 6 | |||
| 4 | 6.5 | |||
| Year 2 | 1 | 5.8 | ||
| 2 | 5.2 | |||
| 3 | 6.8 | |||
| 4 | 7.4 | |||
| Year 3 | 1 | 6 | ||
| 2 | 5.6 | |||
| 3 | 7.5 | |||
| 4 | 7.8 | |||
| Year 4 | 1 | 6.3 | ||
| 2 | 5.9 | |||
| 3 | 8 | |||
| 4 | 8.4 | |||
| Quarter Data for Car Sales | ||||
| Year | Quarter | Sales (1000's) | Moving average (4) | Center moving average (baseline) |
| year 1 | 1 | 4.80 | ||
| 2 | 4.10 | |||
| 5.35 | ||||
| 3 | 6.00 | 5.48 | ||
| 5.60 | ||||
| 4 | 6.50 | 5.74 | ||
| 5.88 | ||||
| Year 2 | 1 | 5.80 | 5.98 | |
| 6.08 | ||||
| 2 | 5.20 | 6.19 | ||
| 6.30 | ||||
| 3 | 6.80 | 6.33 | ||
| 6.35 | ||||
| 4 | 7.40 | 6.40 | ||
| 6.45 | ||||
| Year 3 | 1 | 6.00 | 6.54 | |
| 6.63 | ||||
| 2 | 5.60 | 6.68 | ||
| 6.73 | ||||
| 3 | 7.50 | 6.76 | ||
| 6.80 | ||||
| 4 | 7.80 | 6.84 | ||
| 6.88 | ||||
| Year 4 | 1 | 6.30 | 6.94 | |
| 7.00 | ||||
| 2 | 5.90 | 7.08 | ||
| 7.15 | ||||
| 3 | 8.00 | 7.15 | ||
| 4 | 8.40 | |||
Using Trend based forecasting in Excel, we get the following forecast for Year 5. In order to get this forecasting , the following steps are followed.. Select the Actual sales -> Data - > Forecast Sheet
| Quarter | Actual Sales (1000's) | Forecasted Sales (1000's) | |
| year 1 | Year1-Q1 | 4.800 | |
| Year1-Q2 | 4.100 | ||
| Year1-Q3 | 6.000 | ||
| Year1-Q4 | 6.500 | ||
| Year 2 | Year2-Q1 | 5.800 | |
| Year2-Q2 | 5.200 | ||
| Year2-Q3 | 6.800 | ||
| Year2-Q4 | 7.400 | ||
| Year 3 | Year3-Q1 | 6.000 | |
| Year3-Q2 | 5.600 | ||
| Year3-Q3 | 7.500 | ||
| Year3-Q4 | 7.800 | ||
| Year 4 | Year4-Q1 | 6.300 | |
| Year4-Q2 | 5.900 | ||
| Year4-Q3 | 8.000 | ||
| Year4-Q4 | 8.400 | ||
| Year 5 | Year5-Q1 | 7.33 | |
| Year5-Q2 | 6.64 | ||
| Year5-Q3 | 8.44 | ||
| Year5-Q4 | 9.00 |
The green colored values are the forecasted value for each quarter of year 5


