Section 4: Model Building a) For the E-Commerce Retail Sales (Million\$) data given in the table below, provide estimates from the 1st Quarter (Q1) of 2014 to the 3rd Quarter (Q3) of 2015 by using two models: 1) Single Exponential Smoothing with =0.3 2) Trend Naive model. Calculate MAD for each model. b) Compare two models above (Single Exponential Smoothing and Trend Naive) based on their accuracies. Which forecasting method appears to be better? Using the model you choose, provide forecast for the 4th Quarter (Q4) of 2015. Assuming that absolute percentage error for your Q4 of 2015 forecast is 20% and that you underestimated the actual value, find the actual value. c) Some residual graphs from the first forecast model (including wider range of E-Commerce Retail Sales data) are given below. What do these graphs tell about the model? Explain each graph. Section 4: Model Building a) For the E-Commerce Retail Sales (Million\$) data given in the table below, provide estimates from the 1st Quarter (Q1) of 2014 to the 3rd Quarter (Q3) of 2015 by using two models: 1) Single Exponential Smoothing with =0.3 2) Trend Naive model. Calculate MAD for each model. b) Compare two models above (Single Exponential Smoothing and Trend Naive) based on their accuracies. Which forecasting method appears to be better? Using the model you choose, provide forecast for the 4th Quarter (Q4) of 2015. Assuming that absolute percentage error for your Q4 of 2015 forecast is 20% and that you underestimated the actual value, find the actual value. c) Some residual graphs from the first forecast model (including wider range of E-Commerce Retail Sales data) are given below. What do these graphs tell about the model? Explain each graph