If a haystack in the shape of a right circular cone has a base radius of 5 meters and contains 12 tons of hay, what will be the number of tons of hay in a similar conical haystack whose base diameter is 18 meters? Two right cones are similar if their heights and their base radii are in proportion. Express your answer as a decimal to the nearest tenth.
radius 1 = 5 height = h
radius 2 = 9 m height = 9/5 h
volume 1 = 12 tons/volume
1/3 pi 5^2 h = 12 remove the constants 25h = 12 tons h = 12/25
1/3 pi 9^2 (9/5)h = 81(9/5)h = ? 81* 9/5 * 12/25 = 69.98=~~70 tons
(not positive of this answer!)