Westonci.ca is the ultimate Q&A platform, offering detailed and reliable answers from a knowledgeable community. Ask your questions and receive precise answers from experienced professionals across different disciplines. Connect with a community of professionals ready to help you find accurate solutions to your questions quickly and efficiently.

z varies directly as square-root of x and inversely as y. If z = 147 when x = 16 and y = 6, find z if x = 25 and y = 4. (Round off your answer to the nearest hundredth.)

Sagot :

SOLUTION

From the question

[tex]\begin{gathered} z\propto\sqrt[]{x}\text{ and } \\ z\propto\frac{1}{y} \\ \text{combining we have } \\ z\propto\frac{\sqrt[]{x}}{y} \\ \propto\text{ is a proportionality constant } \end{gathered}[/tex]

Removing the proportionality sign and introducing a constant, we have

[tex]\begin{gathered} z=k\times\frac{\sqrt[]{x}}{y} \\ z=\frac{k\sqrt[]{x}}{y} \end{gathered}[/tex]

Making k the subject, we have

[tex]\begin{gathered} z=\frac{k\sqrt[]{x}}{y} \\ k\sqrt[]{x}=yz \\ k=\frac{yz}{\sqrt[]{x}} \end{gathered}[/tex]

Substituting the initial values of z, x, and y, we have

[tex]\begin{gathered} k=\frac{yz}{\sqrt[]{x}} \\ k=\frac{6\times147}{\sqrt[]{16}} \\ k=\frac{882}{4} \\ k=220.5 \end{gathered}[/tex]

The relationship becomes

[tex]z=\frac{220.5\sqrt[]{x}}{y}[/tex]

Substituting the second values of x and y into the equation for the relationship, we have

[tex]\begin{gathered} z=\frac{220.5\sqrt[]{x}}{y} \\ z=\frac{220.5\sqrt[]{25}}{4} \\ z=\frac{220.5\times5}{4} \\ z=\frac{1,102.5}{4} \\ z=275.625 \end{gathered}[/tex]

Hence the answer is 275.63 to the nearest hundredth