Answer:
3,848 feet.
Explanation:
1) Square 70
2) Multiply 4,900 (the square of 70) by pi
3) Divide 15,393.804 (4,900 times pi) by 4 (to find a quarter of the tank)
4) Round 3,848.451 (15,393.804 divided by 4) to the nearest whole number and you get 3,848 feet.
I hope this helps.