<PRE><B>Question 620628</B>
Hello, 
The formula to use is:
V=pi(r)^2h
Convert 4.1 miles to feet by multiplying it by 5280 to get:
21648 feet
Plug in the values:
4200 cubic feet=3.14r^2(21648)
Expand this out:
4200 cubic feet=r^2(67974.72)
Divide 67974.72 feet
.0618 square feet=r^2
Square root both sides to get:
.25 feet (approx) or 3 inches radius.
Make sense?
RJ
www.math-unlock.com
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