A regression trend analysis uses only the information contained in the passage of time to predict a response variable.
1. Perform a trend analysis with the Colorado Combined Campaign data, using Actual as the response variable and Year as the predictor.
2. Forecast the 2010 – 2013 Colorado Combined Campaign contributions.
3. Compare your forecast for 2010 with that obtained from the simple linear regression model in which number of eligible employees is the predictor variable. Hint: Compare RMSE, RSquare, and the estimated contributions for 2010. Which model does a better job of explaining variation in contributions?
4. We’ve limited our analyses to one predictor variable at a time. Guestimate what would happen, in terms of RMSE, RSquare and model predictions if we were to build a model with both Year and Employees.