Answers:
Variation Constant: k = 7/6
y = 245/6 when x = 7 and z = 5
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Explanation:
"y varies jointly as x and z" means that y = kxz
We have (x,y,z) = (4,14,3) as one triple, so,
y = kxz
14 = k*4*3
14 = 12k
12k = 14
k = 14/12
k = 7/6 is the variation constant
The equation goes from y = kxz to y = (7/6)xz
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Plug in x = 7 and z = 5 to find y
y = (7/6)xz
y = (7/6)*7*5
y = (7/6)*(7/1)*(5/1)
y = (7*7*5)/(6*1*1)
y = 245/6
