The speed limit on a road is 60 mph. the actual speeds of cars are measured and found to be normally distributed with a mean value of 63 mph and a standard deviation of 5 mph. approximately what percentage of cars exceed the speed limit by more than 10 mph?
a) 5.0%
b) 6296%
c) 7.3%
d) 8.1%

 8.1%

Step-by-step explanation:

Given :

Let x be the random variable that represents the actual speeds of cars.

The speed limit on a road is 60 mph.

Using formula , , we have for x= 60+10=70

Using z-table for right-tailed test value, The probability of  cars exceed the speed limit by more than 10 mph will be

Hence, the percentage of cars exceed the speed limit by more than 10 mph is 8.1%.