MTN Group Limited, is a South African multinational mobile telecommunications company, operating in many African and Asian countries. As December 2020, MTN recorded 280 million subscribers, making it the 8th largest mobile network operator in the world and the largest in Africa. The following table reports sales (in units) at one of its branches in Cape Town for the past 18 months. The branch's manger wants an accurate method for forecasting future sales. Month 1 2 3 4 5 6 Sales Month 293 7 283 8 322 9 355 10 346 11 379 12 Sales 381 431 424 433 470 481 Month 13 14 15 16 17 18 Sales 549 544 601 587 644 660 2.1. Use exponential smoothing with a = 0.3, 0.4 and 0.5. which value of a provides the best (8) forecasts? 2.2. Use trend projection to provide a forecast. What is the value of MSE? 2.3. Which method of forecasting would you recommend to the manager? (6) (2) [16 marks] Global Marine Sea Tech, GMS, are leading specialists in delivering the very best of electronics used for marine and outdoor navigation, communication, safety, and entertainment. GMS has been an authorised dealer for Regal marine GPS for the past 7 years. The following table reports the quarterly number of GPS sold each year. Year 1 2 3 4 5 6 7 Quarter 1 6 10 14 19 22 24 28 Quarter 2 15 18 26 28 34 36 40 Quarter 3 10 15 23 25 28 30 35 Quarter 4 4 7 12 18 21 20 27 1.1. Show a graph of this time series. (2) (4) 1.2. Develop the equation for the linear trend component of the time series. 1.3. Use the linear trend to forecast the quarterly sales values in year 8. (2) 1.4. Perform an analysis of the seasonality of the data. Indicate the seasonal indexes for each period, and comment on the high and low seasonal sales periods. 1.5. When does GMS experience the largest seasonal effect? (12) (2) 1.6. Compute the MAPE. (6) 1.7. Use the multiplicative seasonal model to forecast the GMS quarterly sales values in year 8. (6) [34 marks]