Ineed on finding the scientific notation for number 1

1.  Total area of water = 352,000,000 + 9 * 10^6

= 352,000,000 + 9,000,000 = 361,000,000 = 3.61 * 10^8

Fraction of the surface covered by water =   3.61 * 10^8 /  5.1 * 10^8

= 3.61 / 5.1  =   0.707843   = 70.78 % to nearest hundredth of a percent.