Annual sales of a company (in million taka) are given below. Year 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 Sales 13 12 14 16 11 14 16 15 17 16 18 (a) Assuming w1 = 0.4 and w2 = 0.6 are weights, select the best weight W in exponential smoothing and compute the smoothed data, visualize smoothed data in a scatterplot and comment on the trend. (b) Obtain one-step ahead recursive forecast for the year 2020 by using 3-MA and exponential smoothing in your question (a). If the original sales for the year 2020 is 16 million taka, find the most preferred method for forecasting.