C(t) = 47,863,000 + 430,500t + 178t2
P(t) = 44,178,000 + 78,000t
a.) To find the state's per capita health care costs, we need to divide the cost function by the population function. Let's simplify by using some factoring technique. Here we have:
178t2 + 430,500t + 47,863,000 = 2*(89t2 + 215,250t + 23,931,500)
78,000t + 44,178,000 = 6000*(13t + 7363)
C(t)/P(t) = 2*(89t2 + 215,250t + 23,931,500) / 6000*(13t + 7363)
= 89t2 + 215,250t + 23,931,500 / 3000*(13t + 7363)
b.) To find the average rate of change for the per capita health care costs, use the following:
Average ROC = [C(t2) - C(t1)] / t2 - t1 = [C(8) - C(4)] / 8 - 4 = (51,318,392 - 49,587,848) / 4 = 432,636
The average ROC for the per capita health care costs is about $432,636 per citizen.