please round answer

Based on annual driving of 14,600 miles and fuel efficiency of 20 mpg, a car in the United States uses, on average, 730 gallons of gasoline per year. If annual automobile fuel usage is normally distributed, and if 26.76% of cars in the United States use less than 520 gallons of gasoline per year, what is the standard deviation? (Round your answers and z values to 2 decimal places, eg. 1.25. Round your answer to 3 decimal places, eg. 2.531.)