To solve this you must set up what is called a proportion. Â A proportion is a way of comparing two comparing values where one of the four values is missing. Â In your problem the missing value is the height of the smallest tree in the model.
To set up a proportion, you need all of your values. Â The easiest way to do this is to list them:
Highest tree in real life: Â 40ft
Highest tree in model: Â 10ft
Smallest tree in real life: Â 4ft
Smallest tree in model: Â x
So know you can set your proportion like this:
40/4 = 4/x
(When setting up a proportion, you always want to have the values belong to each other. Â For example don't put the height of the small tree in the model underneath the value of the highest tree in real life.)
So know to find what the x values equals, we need to cross multiply. Â And then all that's left after that is to solve for x.
40 times x = 4 times 4
40x = 16
x = 2.5
The smallest tree in the model should equal 2.5 feet.
Hope this helps! :)