A twenty-foot equivalent unit (TEU) is a standard measurement of volume in container shipping. The majority of

Question:

A twenty-foot equivalent unit (TEU) is a standard measurement of volume in container shipping. The majority of containers are either 20 or 40 feet in length. A 20-foot container is 1 TEU; a 40-foot container is 2 TEUs. Although the height of containers can also vary, this does not affect the TEU measurement. The following data are the total number of containers shipped from the port of Los Angeles for the years 1995 through 2007.

A twenty-foot equivalent unit (TEU) is a standard measurement of

a. Plot the series. What can you learn from examining this plot?

b. Calculate and display the first 24 autocorrelations for the series. What do the ACF and PACF suggest about the series?

c. Suggest and estimate an optimal set of differencing to use with the series.

d. Estimate the ARIMA model that you believe to be a good candidate for forecasting container shipments. It may help to specify the seasonality as "12." Test the Ljung-Box statistic and report your findings. Finally, plot the first 24 autocorrelations of the residuals to your best model.