9. The diameter of the Earth is 7899.83 miles from the North Pole to the South Pole and 7926.41 miles from opposite points at the equator. a. Find the approximate surface area of Earth using each measure.
b. About 75% of Earth's surface is covered by water. Find the surface area of water on Earth, using the diameter of the Earth is 7926.41 miles from opposite points at the equator.

We could think of the Earth as a sphere, where the diameter of this sphere will the mean diameter between the measure from the North pole to the Soth pole and the measure from opposite points of the equator.

Remember that the mean between two numbers A and B is:

Mean = (A + B)/2

In this case, the mean diameter will be:

D = (7,899.83mi + 7,926.41mi)/2 = 7,913.115 mi

And we know that the surface of a sphere of diameter D is:

S = 4*pi*(D/2)^2

Where pi = 3.14

Then the surface of the Earth will be something like:

S = 4*3.14*(7,913.115mi/2)^2 = 196,618,601.47 mi^2

b) We know that 75% of the Earth's surface is water, now we will use the diameter 7,926.41 mi to compute the surface.

First, the total surface of the Earth will be:

S = 4*3.14*(7,926.41mi/2)^2 = 197,279,843.03 mi^2

And 75% of this is water, then the total water surface is 0.75 times that area, this is:

water surface = 0.75*197,279,843.03 mi^2 = 147,959,882.27 mi^2

answer: e 9, 5.75

step-by-step explanation:

step 1

find the variation ab in the x coordinate

delta x=(x2-x1)=10-> 8 units

find the variation ab  in the y coordinate 

delta y=(y2-y1)=6-> 2 units

step 2

find the coordinates point c

  x coordinate 

cx=ax+delta x*2/> cx=2+8*(2/> cx=3

  y coordinate 

cy=ay+delta y*2/> cy=4+2*(2/> cy=4.25

the coordinates of point c are (3,4.25)

step 3

find the coordinates point d

  x  coordinate 

dx=ax+delta x*4/> dx=2+8*(4/> dx=4

  y  coordinate 

dy=ay+delta y*4/> dy=4+2*(4/> dy=4.5

the coordinates of point d are (4, 4.5)

step 4

find the coordinates point e

  x  coordinate 

ex=ax+delta x*4/> ex=2+8*(6/> ex=5

  y  coordinate 

ey=ay+delta y*4/> ey=4+2*(6/> ey=4.75

the coordinates of point e are (5, 4.75)

step 5

find the coordinates point f

  x  coordinate 

fx=ax+delta x*4/> fx=2+8*(8/> fx=6

  y  coordinate 

fy=ay+delta y*4/> fy=4+2*(8/> fy=5

the coordinates of point f are (6,5)

step 6

find the coordinates point g

  x  coordinate 

gx=ax+delta x*4/> gx=2+8*(10/> gx=7

  y  coordinate 

gy=ay+delta y*4/> gy=4+2*(10/> gy=5.25

the coordinates of point g are (7,5.25)

step 7

find the coordinates point h

  x  coordinate 

hx=ax+delta x*4/> hx=2+8*(12/> hx=8

  y  coordinate 

hy=ay+delta y*4/> hy=4+2*(12/> hy=5.5

the coordinates of point h are (8,5.5)

step 8

find the coordinates point i

  x  coordinate 

ix=ax+delta x*4/> ix=2+8*(14/> ix=9

  y  coordinate 

iy=ay+delta y*4/> iy=4+2*(14/> iy=5.75

the coordinates of point i are (9,5.75)

- r3ktforgood ☕

36 girls

step-by-step explanation:

the 48 boys is 4 parts of the ratio

divide 48 by 4 to obtain one part of the ratio

= 12 ← 1 part of the ratio

3 parts = 3 × 12 = 36 ← number of girls