Fitting a Trend Line and Forecasting (VCE SSCE General Mathematics): Flashcards
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Method to fit trend line to time series data
Method to fit trend line to time series data
Least squares method
What least squares method minimises
What least squares method minimises
Squared distances between data points and line
Variable type: time (year/quarter) in trend line fitting
Variable type: time (year/quarter) in trend line fitting
Explanatory variable (EV)
Variable type: measurement (sales, etc.) in trend fitting
Variable type: measurement (sales, etc.) in trend fitting
Response variable (RV)
What trend line slope tells you
What trend line slope tells you
Average rate of change per time period
Using fitted line equation to predict future values
Using fitted line equation to predict future values
Trend line forecasting
Purpose of deseasonalising data
Purpose of deseasonalising data
To remove seasonal variation before fitting trend line
How to reseasonalise a prediction
How to reseasonalise a prediction
Multiply by the appropriate seasonal index
DSR process steps in seasonal forecasting
DSR process steps in seasonal forecasting
Deseasonalise, Substitute, Reseasonalise
Caution when predicting far beyond original data range
Caution when predicting far beyond original data range
Treat results with caution; trends may not continue