Question

A balloon has a circumference of 28 in. Use the circumference to approximate the volume of the balloon to the nearest square inch.

Answer choices:
3,659 in ^3
11,488 in ^3
2,964 in ^3
944 in ^3

Answer 1

the correct question is
a) A balloon has a circumference of 28 in. Use the circumference to approximate the volume of the balloon to the nearest cubic inch.

or

b) A balloon has a circumference of 28 in. Use the circumference to approximate the surface area of the balloon to the nearest square inch.

case a)
we know that
circumference=2*pi*r
clear variable r
r=circumference/(2*pi)
circumference=28 in
r=28/(2*pi)----> r=4.46 in

volume of a balloon=(4/3)*pi*r³-----> (4/3)*pi*4.46³----> 371.61 in³
Volume=372 in³

the answer is
372 in³


case b)
we know that
circumference=2*pi*r
clear variable r
r=circumference/(2*pi)
circumference=28 in
r=28/(2*pi)----> r=4.46 in

surface area of a balloon=4*pi*r²-----> 4*pi*4.46²---> 249.83 in²
Surface area=249.83 in²-------> 250 in²

the answer is
250 in²