posted by chrissy on .
oook that site didn't help much I don't need to know how to suck up to my teacher. I need to know how to set up a ratio, can someone help me??
The format for ratios is # : # :: # : #
Example 1: 2 :: 2 : ?
1 is one half of 2... so 2 would be one half of ? Four , of course.
Chrissy, here is an excellent site on how to set up ratios.
thank you ok that sounded simple. but is it always one half of a number or..can you give me an example or a problem and solve it out???
oooo thanks for the site. it will help me alot!
I'm sorry, the site I thought I posted wasn't the same one that was posted.
GuruBlue has given you an excellent site.
The problem you had stated that 2 inches on the blueprint equals 5 feet in the actual room. The problem asks the length of the actual measurement when it's 7 1/2 inches long on the blueprint. Here's the ratio I set up:
2 inches is to 5 feet as 7 1/2 inches is to x (the actual length).
This is shown as:
2 / 5 as 7 1/2 / x
We cross multiply the top of the first fraction with the bottom of the second fraction.
2x = 5 (7 1/2)
2x = 37.5
x = 18.75 = 18 3/4