SOLUTION: I think this is the best place to put this problem- in the book it's under "Variation and Applications" but I see nothing like that listed. So here goes. Instructions given: Write

Algebra ->  Percentage-and-ratio-word-problems -> SOLUTION: I think this is the best place to put this problem- in the book it's under "Variation and Applications" but I see nothing like that listed. So here goes. Instructions given: Write      Log On


   



Question 288727: I think this is the best place to put this problem- in the book it's under "Variation and Applications" but I see nothing like that listed. So here goes.
Instructions given: Write an equation that represents the relationship between the given variables. Use k as the variation constant.
Problem: C varies directly as r, and C=94.2 when r=15.
I'd show my work, but that's the problem. I don't have any work to show. I don't understand what needs to happen here and I can't find a lesson on this. Could anyone please explain this for me??? Thanks for any help offered, I really do appreciate it!

Answer by texttutoring(324) About Me  (Show Source):
You can put this solution on YOUR website!
Recall that the equation of a line is y=mx+b, where m is the slope and b is the y-intercept.

'Varies directly' just means that the slope is constant, and the y-intercept is zero.

The variation constant is just another word for the slope.

C=kr
94.2=k*15
k=6.28
Your equation is:

C=6.28r