Try another version of this question Suppose that `z` varies jointly with `x` and `y` . Find the constant of proportionality `k` if `z = 207.9` when `y = 9` and `x = 3` . Using the `k` from above write the variation equation in terms of `x` and `y` . Using the `k` from above find `z` given that `y = 20` and `x = 13` .
`k =`
`z =`
`z =`
If needed, round answer to 3 decimal places.
Enter DNE for Does Not Exist, oo for Infinity 7.7
`7.7 xy`
2002