4. Vehicle speed in the State Route 99 Tunnel in Downtown Seattle follows a normal distribution. (a) If the mean and standard deviations are 50 m / h and 10 m / h, respectively, what percent of vehicles have a speed between 45 m/ h and 65 m/ h? (b) If the fastest 3% of all vehicles are to be ticketed, what is the minimum speed to be ticketed? (c) If 5% of all vehicles travel less than 40 m / h and 10% travel more than 70 m/h, what are the mean and standard deviation of the vehicle speed