SOLUTION: The cost (c) of materials for a deck varies jointly with the width (w) and the length (l). If c = $470.40 when w = 12 and l = 16, find the cost when w = 10 and l = 25? Be sure to

Algebra ->  Finance -> SOLUTION: The cost (c) of materials for a deck varies jointly with the width (w) and the length (l). If c = $470.40 when w = 12 and l = 16, find the cost when w = 10 and l = 25? Be sure to       Log On


   



Question 1179894: The cost (c) of materials for a deck varies jointly with the width (w) and the length (l).
If c = $470.40 when w = 12 and l = 16, find the cost when w = 10 and l = 25? Be sure to respond in a
complete sentence that explains your answer in relation to the question.

Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
c=k*w*l
470.40=k*12*16=192k
k=2.45
now use k in the second part.
cost=2.45*10*25=$612.50
as the product of width and length increases, cost increases. Here the product to begin with was 192 and the end was 250, so the cost should increase by a factor of 250/192 or 1.302 (rounded).