4.36. Lily Pads Inc. makes swimming and water sport accessories for children. In 1992 they introduced their EZ Glide-On Flippers, and sales during the summer months have increased steadily since the summer of 1992. Observation Year Season Demand 1 1992 Spring 23 2 Summer 51 3 Fall 12 4 1993 Winter 7 5 Spring 30 6 Summer 67 7 Fall 18 8 1994 Winter 14 9 Spring 37 10 Summer 81 11 Fall 21 12 1995 Winter 12 (a) Plot all data and note seasonality. Plot each year's data separately and note increasing trend. (b) Estimate ST, BT, and the seasonal factors. (c) Forecast the sales for spring and summer of 1995.