2. From the data in the file Forecast, calculate the forecasts using nave method, average of all the historical data, and 3 -week moving average. ( 20 points). 3. What is forecasting accuracy? From the data in question 2 and the resulting forecasts, calculate the forecast accuracy for all 3 models using MAE, MSE, and MAPE. Based on the obtained results, which model would you recommend and why? (20 points). 4. What is time-series data? Explain the different time-series patterns in detail with appropriate plots. (20 points). 5. The regional transit authority for a major metropolitan area wants to determine whether there is a relationship between the age of a bus and the annual maintenance cost. A sample of 10 buses is shown in the datafile AgeCost. ( 20 points). a. Develop a scatter chart for these data. What does the scatter chart indicate about the relationship between age of a bus and the annual maintenance cost? (4 points). b. Use the data to develop an estimated regression equation that could be used to predict the annual maintenance cost given the age of the bus. What is the estimated regression model? (4 points). c. Test whether each of the regression parameters 0 and 1 is equal to zero at a 0.05 level of significance. What are the correct interpretations of the estimated regression parameters? (4 points). d. How much of the variation in the sample values of annual maintenance cost does the model you estimated in part (b) explain? (4 points). e. What do you predict the annual maintenance cost to be for a 3.5 -year-old bus? (4 points). \begin{tabular}{|r|r|l|} \hline Week & \begin{tabular}{l} Time \\ Series \\ Value \end{tabular} & Forecast \\ \hline 1 & 100 & \\ \hline 2 & 200 & \\ \hline 3 & 320 & \\ \hline 4 & 250 & \\ \hline 5 & 350 & \\ \hline 6 & 420 & \\ \hline 7 & 370 & \\ \hline 8 & 457 & \\ \hline 9 & 239 & \\ \hline 10 & 422 & \\ \hline 11 & 355 & \\ \hline 12 & 444 & \\ \hline 13 & 334 & \\ \hline 14 & 445 & \\ \hline 15 & 555 & \\ \hline \end{tabular} \begin{tabular}{|c|c|} \hline Age of Bus (years) & Annual Maintenance Cost (\$) \\ \hline 1 & 350 \\ \hline 2 & 370 \\ \hline 2 & 480 \\ \hline 2 & 520 \\ \hline 2 & 590 \\ \hline 3 & 550 \\ \hline 4 & 750 \\ \hline 4 & 800 \\ \hline 5 & 790 \\ \hline 5 & 950 \\ \hline \end{tabular}