The value of y varies jointly with the values of x and z. When x = 5 and z = 10, the value of y is 600. What is the value of y when x = 4 and z = 9?
A. 156
B. 480
C. 12
D. 432
We can use the joint variation formula to solve for y:
y = kxz
where k is the constant of variation. We can find k by plugging in the given values:
600 = k(5)(10)
k = 12
Now we can use k to find y when x = 4 and z = 9:
y = (12)(4)(9) = 432
Therefore, the answer is D. 432.