SOLUTION: Z is jointly proportional to x^2 and y^3. If z=401 when x=3 and y=4, find z when x=6_ and y=5

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Question 1075364: Z is jointly proportional to x^2 and y^3. If z=401 when x=3 and y=4, find z when x=6_ and y=5
Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
z=kx^2y^3
solve for k
401=k*9*64
k=401/576
z=(401/576)*36*125
=3132.8125
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check doubling of x should increase 4 fold and increasing y 25% should increase 1.953 fold or a total of 7.612125 fold. That number*401 gives the number above.