We are interested to determine how well new car models protect the driver and front-seat passenger in a head-on collision. The important variable to be measured is the severity of a driver's head injury when the car is in a head-on collision with a fixed barrier while travelling at 35 miles per hour. The more points assigned to the head injury rating, the more severe is the injury. Assume the head rating injuries are approximately normally distributed with a mean of 605 points and a standard deviation of 185 points. One of the crash-tested cars is randomly selected and the driver's head injury rating is observed.

1. What is the probability the head injury rating will be less than 580 point

2.What is the probability the head injury rating falls between 400 and 600 points?

3.Suppose we know a head injury is the 44th percentile. What would the value of the injury be?

4.If 5 crash-tested cars are randomly and independently sampled, what is the probability the average driver's head injury is less than 590?