3. REGRESSION (LINEAR TREND LINE), a. Calculate Regression forecasts for Demand (Y): dependent variable; and Weeks (X) is the independent variable), a: intercept (constant), b: slope Linear equation (a+bX) : VERIFY: a (intercept from EXCEL) = using intercept function =1307.6 b( slope from EXCEL )= using slope function =1.763 Solutions: Week 12=Y1=a+bX1=1307.6+(1.763)12=1286.44 Week 13=a+b X2 =1307.6+(1.763)13= Week 14= b. MAD: MSE: MAPE: Which forecasting method needs to be selected for short term forecasting? Why? Which forecasting method needs to be selected for long term forecasting? Why