Question

Select the letter of the correct answer

A woman sailed around the globe. Suppose the circumference of the world is 24,901 miles.
Estimate the world's radius in kilometers. Round your answer to the nearest whole kilometer.
Hint
A
6,384 kilometers
B
3,965 kilometers
C
3,256 kilometers
D
7,320 kilometers
It’s b

Answer 1

The estimate value of the world's radius is 6384 kilometers ⇒ A

Explanation:

The formula of the circumference of a circle is C = 2πr, where r is the radius of the circle

∵ The circumference of the world is 24,901 miles

∵ C = 2πr

- Substitute C by 24,901 to find r

∴ 24,901 = 2πr

- Divide both sides by 2π

∴
`(24,901)/(2\pi )` = r

∴ The radius is 3965.127389 miles

Change the mile to kilometer

∵ 1 mile = 1.60934 kilometers

- Multiply the value of the radius by 1.60934

∴ r = 3965.127389 × 1.60934

∴ r = 6381.238111 kilometers

- Round it to the nearest kilometers

∴ r = 6381 kilometers

The world's radius is 6381 kilometers

The nearest choice for this value is A

The estimate value of the world's radius is 6384 kilometers