Suppose that the speed at which cars go on the freeway is normally distributed with mean 70 mph and standard deviation 6 miles per hour. Let X be the speed for a randomly selected car. Round all...

Suppose that the speed at which cars go on the freeway is normally distributed with mean 70 mph and standard deviation 6 miles per hour. Let X be the speed for a randomly selected car. Round all answers to 4 decimal places where possible.






 81% of all cars travel at least how fast on the freeway?  mph.