SOLUTION: I need help solving this problem. There is a table given that says weight in pounds, x: 5,10,15 then cost to mail, y: $7, $11, $15 then it asks.. How much does it cost per

Algebra ->  Rate-of-work-word-problems -> SOLUTION: I need help solving this problem. There is a table given that says weight in pounds, x: 5,10,15 then cost to mail, y: $7, $11, $15 then it asks.. How much does it cost per       Log On


   



Question 368805: I need help solving this problem.
There is a table given that says weight in pounds, x: 5,10,15
then cost to mail, y: $7, $11, $15
then it asks..
How much does it cost per pound to mail a package?
Then.. What would a 16 pound package cost to mail?
Thanks for the help!

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
There is a table given that says
weight in pounds, x: 5, 10, 15
then cost to mail, y: $7, $11, $15
then it asks..
How much does it cost per pound to mail a package?
Then.. ----
slope = (11-7)/(10-5) = 4/5 = 80 cents per pound
-----
Equation:
y = mx+b
7 = (4/5)5 + b
b = 3
---
Equation:
c(x) = (4/5)x + 3
What would a 16 pound package cost to mail?
c(16) = (4/5)*16 + 3
c(16) = 64/5+3 = $15.80
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Cheers,
Stan H.
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