06. Suppose that the last four months of sales were 8, 10, 15, and 9 units, respectively. Suppose further that the last four forecasts were 5, 6, 11, and 12 units, respectively. What is the Mean Absolute Deviation (MAD)? (3 pts.) 07. If alpha(a) is 0.2 and the current demand is 200, the forecast for the current period was 175 and for the last period was 150; what is the forecast for the next period? (3 pts.) * Using the data below, give your answers for the following questions: Period Demand ($000) 2017 50 2018 -- 40 2019 45 2020 35 2021 40