For all types of animals, the percentage that survive into the next year decreases. In one study, the survival rate of a sample of reindeer was modeled by S(t) = 100(0.999993)^t5. The function S outputs the percentage of reindeer that survive t years. 

(a) Evaluate S(4) and S(15). Interpret the results. 

(b) Graph Sin [0, 15, 5] by [0, 110, 10]. Interpret the graph. Does the graph have a horizontal asymptote?