The average fuel efficiency for a vehicle driving on a highway is 21 mpg with a standard deviation of 4 mpg. What is the probability that while driving a 10-mile segment of highway, one hundred...

The average fuel efficiency for a vehicle driving on a highway is 21 mpg with a standard deviation of 4 mpg. What is the probability that while driving a 10-mile segment of highway, one hundred randomly chosen vehicles use a total of more than 58 gallons of fuel? (Hint: A sum isn X× .)