Suppose you had the following data on sales (in units). Calculate a Naive 2 forecast for 2017 (time period 4) fusing a change factor of c = 0.31, to three decimal places. Year Sales 2014 247 2 2015 498 3 2016 425Suppose we have the time series data )' below along with the first-difference data D. tim Dt e (t) 7 5 N/A 2 8 3 5 6 5 Calculate and input the values of the first differenced series