7) So when x=6 then z=72, they are directly proportional, so if I multiply the first with a number, then I have to multiply the second with the same number.
6 becomes 13 (x) /multiplied with about 2.167/
72 becomes 156(y) /multiplied with about 2.167/
8) Inversely proportional, so if I multiply the first with a number, then I have to divide the second with the same number.
6 becomes 13 (x)
2 becomes ~0.92307(y) /round it to the thousandths place and you get 0.923/