Suppose the average number of vehicles arriving at the main gate of an amusement park is equal to 10 per minute, while the average number of average waiting time in minutes for each vehicle at the gate is given by f(x)=- where x> 10. X-5 x-10x (a) Estimate the admittance rate x that results in an average wait of 30 seconds. (b) If one attendant can serve 4 vehicles per minute, how many attendants are needed to keep the average wait time 30 seconds or less? (a) Estimate the admittance rate x that results in an average wait of 30 seconds. The admittance is about vehicles per minute. (Round to the nearest tenth as needed.)