Final answer:
To determine how many times greater the water-covered area of Earth is than the land-covered area, add the surface areas of saltwater and freshwater, subtract this total from the Earth's entire surface area to get the land-covered area, and then divide the water-covered surface area by the land-covered area to find the ratio, which is approximately 2.4 times.
Step-by-step explanation:
The question asks to compare the amount of Earth's surface covered by water to the amount covered by land. To calculate this ratio, we first add the surface area of all the saltwater, which is around 352,000,000 km², to the surface area of all the freshwater, which is approximately 9 x 10¶ km². This combined total of water-covered surface area is approximately 361,000,000 km².
Since the Earth's total surface area is roughly 5.1 x 10⁸ km², the amount of Earth's surface covered by land is the difference between these two figures, which can be found by subtracting the water-covered surface area from the total surface area. Therefore, the surface covered by land is about (5.1 x 10⁸) - 361,000,000 km².
To find how many times greater the water-covered area is compared to land, we divide the water-covered surface area (361,000,000 km²) by the land surface area. Before we can do that, we need the exact figure for the land surface area: 5.1 x 10⁸ km² - 361,000,000 km² = 149,000,000 km² (rounded to one decimal place). Therefore, the water-covered surface area is (361,000,000 / 149,000,000) times greater than the land-covered surface, which is approximately 2.4 times.