We are looking at the equation where y varies jointly as x and the square root of z. The initial equation that represents this relationship is written as
![y=kx\sqrt[]{z}](https://img.qammunity.org/2023/formulas/mathematics/college/28ug695h2l6kexazoi824fn6dvbh3i4fe6.png)
where k is the proportionality constant. We need to solve for the value of k given that at x = 1 and z = 16, the value of y is equal to 16. This is done as follows:
![\begin{gathered} 16=k(1)(\sqrt[]{16}) \\ 16=4k \\ (4k)/(4)=(16)/(4) \\ k=4 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/kieibmpsiboc1jjyvxcoj183nrwypqvf5i.png)
Therefore, the equation that shows the relationship of y to x and z is written as
![y=4x\sqrt[]{z}](https://img.qammunity.org/2023/formulas/mathematics/college/vlowue3ecxsl5gjvxzenv4pud45ww34bvu.png)