Stephanie M. answered 07/31/15
Tutor
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Degree in Math with 5+ Years of Tutoring Experience
When Z is directly proportional to X, that means that, for some number m, Z = mX.
Let's solve for m, knowing that when X = 3, Z = 0.94736842105263:
Z = mX
0.94736842105263 = m(3)
0.315789474 = m
So, when X = 13:
Z = mX
Z = 0.315789474(13)
Z = 0.315789474
When Z is inversely proportional to Y, then, for some number n, Z = n/Y.
Let's solve for n, knowing that when Y = 19, Z = 0.94736842105263:
Z = n/Y
0.94736842105263 = n/19
18 = n
So, when Y = 26:
Z = n/Y
Z = 18/26
Z = 0.692307692