Fuel efficiency (miles per gallon) 15 2 289 3 3555666 4 3799 5 339 Key: 15 means a fuel efficiency of 15 miles per gallon. (a) What is the highest fuel efficiency in the 40s? (b) What is the lowest fuel efficiency in the sample overall? (c) How many cars in the sample have fuel efficiencies in the 20s?​