How do you solve proportions?

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Answer 1 · 2018-06-03T20:52:48

Solving proportions is like solving fractions:

$a:b -> c:d$ can be rewritten as $a/b = c/d$ and now you can solve for any of the variables.

See an example below:

3 to 4 is like what to 16?

This can be rewritten as a proportion:

$3:4 -> c:16$

Which can be rewritten as:

$3/4 = c/16$

Which can be solved as:

$color(red)(16) xx 3/4 = color(red)(16) xx c/16$

$cancel(color(red)(16))color(red)(4) xx 3/color(red)(cancel(color(black)(4))) = cancel(color(red)(16)) xx c/color(red)(cancel(color(black)(16)))$

$12 = c$

$c = 12$

3 to 4 is like 12 to 16?