The values of Alabama building contracts (in millions of dollars) for a 12-month period

follow.

240 350 230 260 280 320 220 310 240 310 240 230

a. Construct a time series plot. What type of pattern exists in the data?

b. Compare a three-month moving average forecast with an exponential smoothing fore-

cast. use a= 0.2. Which provides the better forecasts based on MSE?

c. What is the forecast for the next month?