Question

A cartographer is painting a spherical globe whose surface is 326.7 sq. in. What is the maximum radius of the globe that the cartographer is painting? Use 3.14 for π.

5.1 in
4.3 in
26.0 in
13.1 in

Answer 1

5.1

Explanation:

The equation for the surface area of a sphere is SA=4πr2 (that is squared, not a 2)

So plug in the known values:

326.7=4(3.14)r2 Multiply 4 x 3.14

326.7=12.56r2 Divide by 12.56

26.0111=r2 Get the square root

5.0110=r

This simplifies to 5.1, which is the maximum radius of the globe.

I would recommend going back to the course and writing all of the equations on page 6 down, or printing the segment review page from resources in the course. This will hwlp you with those problems in the future.

Answer 2

`S =4\pi r^2`

And since we know the surface area 326.7 in^2 we can solve for the value of r like this:

`r =\sqrt{(S)/(4 \pi)}`

And replacing we got:

`r =\sqrt{(326.7 in^2)/(4 (3.14))}= 5.10 in`

And the best answer would be:

5.1 in

Explanation:

For this case we need to use the formula for the surface area of a sphere given by:

`S =4\pi r^2`

And since we know the surface area 326.7 in^2 we can solve for the value of r like this:

`r =\sqrt{(S)/(4 \pi)}`

And replacing we got:

`r =\sqrt{(326.7 in^2)/(4 (3.14))}= 5.10 in`

And the best answer would be:

5.1 in