Problem 3. ABC company is experimenting with two forecasting methods for its product. Table 2 gives the actual sales and the forecasts obtained by the two methods during the past 6 months. (a) Calculate MAD, MSE, and BIAS for the two methods. (b) Calculate and plot the tracking signals for the two methods. () Are the methods under-forecasting or over-forecasting? Which method would you recommend for forecasting future sales and why? Table 2 Sales Data and Forecasting Results | Month 541 1 2 3 4 5 6 Actual Sales Forecast-1 558 532 490 576 520 632 550 515 575 610 590 Forecast-2 521 538 546 542 555 575