Using the data from exercise 23, estimate (a) a linear trend model with seasonal dummies, and (b) an exponential trend model with seasonal dummies. Which of the two models has a lower MSE and MAD? Use the appropriate model to make forecasts for the next two months.

Data From Exercise 23

Year.............. Month............. Sales

1 .......................Jan.............. 345

1 .......................Feb............. 322

⋮ ...........................⋮...................... ⋮

5....................... Dec......... 10,745