A persons height is 200.0cm. If the Height : Foot length ratio is 5.8, what is the persons footlength?
It’s always a good idea to list your important information first: Foot length: F (F is what we are looking for) (This is called our variable) Height to Foot length Ratio: 5.8 Height of the person: 200.0 cm __H__ = __H__ F F __H__ can be expressed as a ratio. We have that ratio, it’s 5.8! F so we can now plug in our numbers: 5.8 = __200.0cm__ F We can now set up a proportion. We can do this by taking 5.8 and placing it over 1 so that one side of the equal sign resembles the other. __5.8__ = __200.0 cm__ 1 F Now we can cross multiply: 5.8 x F = 1 x 200.0 cm 5.8F = 200.0 cm Since we are looking for F, we have to get F ALONE! We can get F ALONE by separating it from the 5.8 and we do this by dividing both sides by 5.8: __5.8F__ = __200.0 cm__ 5.8 5.8 so 5.8 divided by 5.8 gives us 1F or just F which is what we needed. Note: We divided both sides by 5.8 because what is done to one side must be done to the other side. So F = __200.0 cm__ 5.8 F = 34.5 cm Therefore, the foot length of the pers
