deriving percentage from ratio

To convert a ratio into the form of a percentage,

where two amounts come together on a ratio basis to make a whole, you can derive the percentages by adding the two numbers together to get a measure of the whole.

then divide a part amount by the total and multiply the result by 100.

For example, If the ratio of A to B is 12:4, and you want the percentage of B,

add 12 and 4 to get 16. 4 divided by 16 then times 100 = 25 percentage.

For example, If the ratio of A to B is 12:4, and you want the percentage of A,

add 12 and 4 to get 16. 12 divided by 16 then times 100 = 75 percentage.

This is accurate, easy and very much different from the advice on an on-line help desk, which is: "To convert a ratio into the form of a percentage, simply divide m by n and then multiply the result by 100. For example, If the ratio is 12:4, convert it to the form 12/4, which is an equation we can solve. After that multiply the result by 100 to get the percentage."

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