Algebra help?

Question

1. The variable Z is directly proportional to X, and inversely proportional to Y. When X is 3 and Y is 19, Z has the value 0.94736842105263.

What is the value of Z when X = 13, and Y = 26

2. The variable Z is directly proportional to X. When X is 3, Z has the value 18.

What is the value of Z when X = 13

 

I keep getting these wrong and it would be greatly appreciated if someone could help, even if it is one question!

Answer 1

1.  Z=(kx/y)

.9473.....=(k*3/19)

k=6

 

Z=(6*13/26)

Z=3

 

2.  Z=kx

18=k*3

k=6

Z=6*13

Z=78