Answer:
B. The rate at which the number of people in the park is changing 4 hours after the gates open is 92 people per hour.
Explanation:
Rate at which people enter:
e(x)=0.03x^3 + 2
Rate at which people leave:
L(x)=0.5x + 1
Rate at which the number of people in the park is changing:
(e - L)(x) = 0.03x^3 + 2 - (0.5x + 1) = 0.03x^3 - 0.5x + 1
4 hours after the gates open, the rate is:
(e - L)(4) = 0.03(4)^3 - 0.5(4) + 1 = 0.92 hundreds of people per hour or 0.92*100 = 92 people per hour