Question 5 The table below shows the number of barrels of oil sold by a firm during a year: Month Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec Barrels Sold 51 43 48 49 43 47 52 41 45 49 42 46 (a) Using the data above, calculate the three-point moving average, the trend and seasonal differences using the additive model. [8 marks) (b) Using your calculations from part (a), calculate the average seasonal differences and the adjusted seasonal differences. [4 marks) (c) Assuming trend values of 46 and 42 for January and February respectively next year, forecast the number barrels of oil the firm can expect to sell in January and February next year. Give your answers as whole numbers. [3 marks] Question 5 The table below shows the number of barrels of oil sold by a firm during a year: Month Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec Barrels Sold 51 43 48 49 43 47 52 41 45 49 42 46 (a) Using the data above, calculate the three-point moving average, the trend and seasonal differences using the additive model. [8 marks) (b) Using your calculations from part (a), calculate the average seasonal differences and the adjusted seasonal differences. [4 marks) (c) Assuming trend values of 46 and 42 for January and February respectively next year, forecast the number barrels of oil the firm can expect to sell in January and February next year. Give your answers as whole numbers. [3 marks]