SOLUTION: the mean radius of the earth is 6,371 km, and 70.8% of its surface is covered by water. what is the surface area of the earth covered by land? if 167 cm squared of leather is stitc

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Question 407377: the mean radius of the earth is 6,371 km, and 70.8% of its surface is covered by water. what is the surface area of the earth covered by land? if 167 cm squared of leather is stitched together to make a baseball, what is the radius of the baseball?
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
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the mean radius of the earth is 6,371 km, and 70.8% of its surface is covered by water.
what is the surface area of the earth covered by land?
Surface area of sphere = 4%2Api%2Ar%5E2
:
S.A. = 4%2Api%2A6371%5E2
S.A. = 510,064,472 sq/km total
:
Percent land: 100 - 70.8 = 29.2% land
therefore
.292 * 510064472 = 148,938,826 sq/km is land
:
:
if 167 cm squared of leather is stitched together to make a baseball, what is the radius of the baseball?
Using the Surface area of a sphere again
4%2Api%2Ar%5E2 = 167
r^2 = 167%2F%284%2Api%29
r^2 = 13.28943775
r = sqrt%2813.28943775%29
r = 3.645 inches is the radius of the baseball