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.
 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 />
<em>Dividing both sides by 54 we get:</em>


Therefore, the height of the tree is 22.67 ft.