Arthur's dinner bill totaled $15.72, before sales tax and tip. Sales tax at the restaurant is 5.8%. After sales tax, he left a 15% tip. What was Arthur's total bill, including sales tax and tip?

Sara goes on a slingshot ride in an amusement park. she is strapped into a spherical ball that has a radius 3*10^2 of centimeters. what is the volume of air in the spherical ball? use this formula: volume of a sphere=4/3pi,r^3 , where r is the sphere’s radius.