I'm not sure where to post this question.

There is a recipe that calls for 4 oz. of coffee for a 5 gallon batch.

I will be making a 3 gallon batch. So how much coffee would I need?

I did some looking online and came across this formula:

Desired servings/Original servings

so I did 3/5 = 0.6

so then would I take 0.6 and multply it by 4 oz.

that would give me 2.4 oz.

is that how you do this conversion factor? Like I said, I found it online and don't know if it is reliable. Thanks for the help!