(b) Malaysia cellular phone subscribership has been reported as shown below for the 2009 - 2020 period. Year Subscribers Year Subscribers (Millions) (Millions) 2009 44.0 2015 140.8 2010 55.3 2016 158.7 2011 69.2 2017 182.1 2012 86.0 2018 207.9 2013 109.5 2019 233.0 2014 128.4 2020 255.4 (i) Compute the 4-year centered moving average for the given data. (4 marks) (ii) Using exponential smoothing and the smoothing constant at a = 0.3, what would have been the forecast for year 2021? (7 marks)