SOLUTION: USE A PROPORTION TO SOLVE THE PROBLEM ABOUT DIRECT VARIATION. A shadow cast by an object on a sunny day varies directly as the height of the object. If a person 61 inches tall ca

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Question 135253: USE A PROPORTION TO SOLVE THE PROBLEM ABOUT DIRECT VARIATION.
A shadow cast by an object on a sunny day varies directly as the height of the object. If a person 61 inches tall casts a shadow 57 inches long, how tall is a tree which casts a shadow 42 feet in length?
Found 2 solutions by solver91311, vleith:
Answer by solver91311(24713) About Me  (Show Source):
You can put this solution on YOUR website!
61%2F57=x%2F42 Since 61 and 57 are both in inches and we can express the height of the tree in the same units, feet, as the shadow of the tree, we don't have to worry about conversion of units.

61%2F57=x%2F42

x=%2861%2A42%29%2F57

The calculator says 44.9 and a bunch more decimal digits, but since your LEAST precise measurement is the length of the tree shadow and that is to the nearest foot, you should express your answer to no greater precision. Therefore the answer is 45 feet.

Answer by vleith(2983) About Me  (Show Source):
You can put this solution on YOUR website!
We need to set up a relationship between two sets of numbers.
We are told that the relationship is a direct proportion. we are told that "a person 61 inches tall casts a shadow 57 inches long". So we can setup a ratio that relates those two.
61%2F57
we are also told a tree casts a shadow of 42 feet and then asked to find how tall the tree is.
In words: 61 is to 57 as x is to 42
61%2F57+=+x%2F42
%2861%2A42%29%2F57+=+x+
+50.2feet+=+x