Answer:
30 feet
Explanation:
A ratio of 4:3 means that if one part can be represented by x, the original height is equal to 4 * x and the mural height is equal to 3 * x. This is because the ratio of original : mural is 4 : 3, so if one part = x, we have 4 * x : 3 * x. Therefore,
original mast height = 40 feet
4 * x = original mast height = 40 feet
divide both sides by 4 to get x
x = 10 feet
3 * x = mural mast height = 3 * 10 feet = 30 feet