Answer:
<u>22.67 ft</u> is the height of tree.
Step-by-step explanation:
Given:
Height of a person is 68 in and casts a shadow that is 54 in long.
At the same point, a tree casts a shadow that is 18 ft long.
Now, to find the height of tree.
Let the height of tree be 
If height of a person is 68 in he casts a shadow of 54 in.
So, 68 in is equivalent to 54 in.
Thus,
is equivalent to 18 ft.
Now, to get the height of tree by using cross multiplication method:

<em>By cross multiplying we get:</em>
<em />
<em />
<em>Dividing both sides by 54 we get:</em>


Therefore, the height of the tree is 22.67 ft.