Question

The maximum number of grams of fat (f) that should be in a diet varies directly as a person's weight (w). A person weighing 132 lb should have no more than 88 g of fat per day. What is the maximum daily fat intake for a person weighing 63 lb? Write the equation of variation and solve

Answer 1

Can you build that first variation equation that they are describing?

Answer 2

fw=k? @EulerGroupie

Answer 3

Close... f=kw

Answer 4

I think of "directly" as directly across the equal sign... and k is always there on the right (in the numerator if it's a fraction).
So they always give you the first situation where you will have every number except for k and you will need to solve for it... can you substitute the first numbers they give you into the equation?

Answer 5

88=k132?

Answer 6

Yes, now solve for k so that you can use it in the next step.

Answer 7

.6666

Answer 8

yes... or 2/3 to be exact. Now place that into your original equation to make a model for all future situations... f=(2/3)w.
In the second situation, they give you weight and ask for the corresponding fat.

Answer 9

thanks!

Answer 10

You're welcome.