(a) Using the data of Problem 11.1, fit a regression line
through the data, using t and t 2 as explanatory variables (t is a
time trend 136). Use only the observations from 20002006. Calculate the trend
values using the regression.
(b) Calculate the seasonal factors (multiplicative model)
based upon this trend. How do they compare to the values found in Problem 11.1?
(c) Predict the value of consumers expenditure for 2007
(d) Calculate the seasonal factors using the additive model
and predict consumers expenditure for 2007 Q4.