Income Range ($) | Progressive Tax Rate $40,000 salary/yr 0-10,000
3%
10,000 - 50,000
5%
50,001 - 100,000
5.5%

The diameter of the moon is about 3500 km. approximate the surface area of the moon using the formula for the surface area of a sphere, s = 4πr^2. write your answer in scientific notation.