Forecasting Tutorial 1 Flashcards
When calculating the forecast using the moving average extrapolation method what value is added to?
The last calculated moving average
On a graph with an increasing trend, it is multiplicative if the seasonality…
Is amplified the more the trend continues
In a multiplicative time series, the peaks and troughs of the trend become…
More pronounced as the trend continues
In an additive time series, the peaks and troughs of the series…
Remain at a relatively similar level as the trend continues
How is the ratio of one data point within a multiplicative time series calculated?
Ratio = value / moving average
How are data points normalised?
By dividing the average ratio for comparable points by the average of all ratios
How is the seasonal factor for the multiplicative model calculated?
Value / Moving average
How is the seasonal factor for the additive model calculated?
Value - Moving Average
What should the sum of seasonal factors sum to in the multiplicative model?
1
What should the sum of seasonal factors sum to when using the additive model?
0
