Question

How to solve this 9:n=12:4?

Answer 1

n = 3

Explanation:

What we have here is a ratio. We can use the means-extremes property of proportions to solve this.

The means-extremes property of proportions states that if `a/b = c/d`, which is the same as `a:b = c:d`, then `ad = bc`

So, lets assign values to these variables in the formula:
`Let: a=9, b=n, c=12, and d=4`
This gives us the equation: `9/n=12/4`

To solve, we cross multiply first, giving us: `9 times 4 = 12 times n`

Simplifying gives us: `36 = 12n`

Now we divide both sides by twelve to get n by itself: `36/12 = (12n)/12`

We simplify one last time to get: `3 = n`