please explain step by step

4-2. Using exponentialediate preceding year and 0.3,0.15, and 0.05 for therage with weights of (a) If sales are $45,000 and $50,000 weight of 0.6 on actual values: (The first forecast is equal to the 2010 and 2011, what would you forecast for 2012? (b) Given this forecast and to the actual value of the preceding year.) 2013