Diamond Shamrock Corporation produces liquid chlorine that it ships to its customers Monday through Friday by truckload and railcar. To improve its scheduling, the company’s plant manager would like to develop a forecasting model to predict the tons of chlorine shipped each day for the following week. The following data show the tons of chlorine shipped each day for the past three weeks. These data can also be found in the Excel file chlorine.xlsx.

Tons per Day Shipped Day Week 1 Week 2 Week 3 Monday 177 168 154 Tuesday 130 130 127 Wednesday 136 122 116 Thursday 147 128 138 Friday 192 160 152

a. Construct a graph showing the tons of chlorine shipped over time.

b. Forecast the tons of chlorine shipped each day next week using seasonal dummy variables and a best subsets regression.

c. Interpret the meaning of the coefficients for the seasonal dummy variables.

d. Calculate the MAD for this forecast.

AppendixLO1