Part 2: R practical (24 marks which provide 12% of total) The data below reprosent the monthly salos (in thousands) of product A for a plastics manutacturer for years 1 through 5 (data set plastics). 1. Plot the time series of sales of product A. Can you identify seasonal fuctuations and or a trend? (Short answer) (2 marks) 2. Use a classical multpicative decomporibion to calculabe the trens-cycle and seasonal indices. Multiple choice: trend component changes approximately in the interval- (1) From 1000 to 1300 (2) From 1200 to 1500 (3) From 900 to 1400 (4) From 500 to 1100