A company wants to forecast demand using the weighted moving average. If the company uses three prior yearly sales values (i.e., year 2011 = 160, year 2012 = 140 and year 2013 = 170), and we want to weight year 2011 at 30%, year 2012 at 30% and year 2013 at 40%, which of the following is the weighted moving average forecast for year 2014?
a) 170
b) 168
c) 158
d) 152
e) 146