help thanks so much

Question 3 0/1 pt 9 3 99 @ Details Suppose that the speed at which cars go on the freeway is normally distributed with mean 74 mph and standard deviation 9 miles per hour. Let X be the speed for a randomly selected car. Round all answers to 4 decimal places where possible. a. What is the distribution of X? X - N( 74 Enter an integer or decimal number, accurate to at least 4 decimal places [more..] b. If one car is randomly chosen, find the probability that it is traveling more than 71 mph. c. If one of the cars is randomly chosen, find the probability that it is traveling between 73 and 78 mph. d. 80% of all cars travel at least how fast on the freeway? mph