6. Given the following data, compute MAD, MSE, and MAPE for the following data. Then, please compute the standard deviation of forecast error using the first eight months. 7. Below are a pharmacy's actual sales and forecasted demand for a certain prescription drug for 5 months. How accurate is their forecast? Calculate MAD and MSE and create a control chart. 8. Freight car loadings during a 14-week period at a port are: a) Compute a linear trend line for freight car loadings using of Excel's Trendline, with display Equation on chart option. b) Use the trend equation to predict loadings for weeks 15 and 16