3,857:
1. 3 is located in the thousands place
2. Since 8 is bigger than 3, it's telling it to go up a number (turning 3 into a 4)
Stays the Same: 1,2,3,4
Goes Up: 5,6,7,8, etc.
So 3,857 is now rounded into 4,000
Answer:
<em>L = 24,873.6 miles</em>
Step-by-step explanation:
<u>Length of the Circumference</u>
Given a circle of radius r, the length of the circumference, or line surrounding the shape is:

The Earth has a diameter of 7,917.5 miles. The radius is half the diameter:
r=7,917.5/2=3,958.75 miles
Assuming a plane flies around the equator at ground level, the distance it would travel is:

L = 24,873.6 miles
You can not solve for a as all of the numbers are unknown