... -value
Intercept 37,846.149 4793.353 7.90 < .0001
Time − 17.983 2.397 − 7.50 < .0001
Quarter[Q1] 54.863 35.225 1.56 0.1241
Quarter[Q2] 380.336 35.200 10.81 < .0001
Quarter[Q3] 224.093 35.184 6.37 < .0001

Check the conditions before considering inference. We cannot continue on to inference using this model. The timeplot of the residuals shows that this model does not meet the conditions of the MRM.

A timeplot shows residuals of quarterly car sales from 1990 to 2010. The graph is characterized by sharp rises and falls.

  • ✗ Evidently independent. The model does not explain why sales were falling (it only follows the trend) and omits underlying causal variables. The preceding timeplot of the residuals shows a meandering pattern, and the Durbin-Watson statistic ...

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