The results of a quadratic model fit to time-series data were ŷt = 7.5-0.2t + 2.8t2, where t = 1 for 2002. The forecast value for 2011 is:
A)289.5.
B)285.5.
C)236.1.
D)232.5.

Question

Quizplus · Accepted Answer

To find the forecast value for 2011, we substitute t = 10 (since t = 1 corresponds to 2002) into the model equation: 
ŷ10 = 7.5F1F1F1S1F1F1F10 0.2(10) + 2.8(10)2 = 285.5. Therefore, the forecast value for 2011 is 285.5.

The Results of a Quadratic Model Fit to Time-Series Data