Find the scale factor of the two cylinders:
Figure A has an r of 4 and figure B has an r of 2:
2 / 4 = 0.50, so Figure B is half the size of Figure A.
Since you want the volume, which is measured in cubic units, you need to cube the scale factor:
0.5^3 = 0.125
Multiply the volume of Figure A by the scale factor:
352 x 0.125 = 44 cubic feet.