A company that produces snowboards forecasts monthly sales over the next 2 years to be S = 22.5+ 0.476t+ 4.9 cos where S is measured in thousands of units and t is the time in months, with t = 1 corresponding to January 2017. Predict the sales for each of the following months. (Round your answers to the nearest whole number.) (a) April 2017 S = 24 (b) April 2018 S = 30 (c) October 2017 S = 32 COS(Tt) (d) October 2018 S = 38 X thousand units, X thousand units X thousand units X thousand units