Answer:
(a)k=63.64
(c)y=9.82
Explanation:
Part A
If y is inversely proportional to the square root of x, we have:
[tex]y=\frac{k}{\sqrt[]{x}},\text{ k=constant of proportionality}[/tex]
If y=15 and x=18:
[tex]\begin{gathered} k=y\times\sqrt[]{x} \\ =15\times\sqrt[]{18} \\ =45\sqrt[]{2} \\ k\approx63.640\text{ (correct to 3 decimal places)} \end{gathered}[/tex]
Part B
The variation equation in terms of x is:
[tex]y=\frac{63.64}{\sqrt[]{x}}[/tex]
Part C
When x=42
[tex]\begin{gathered} y=\frac{63.64}{\sqrt[]{42}} \\ y=9.820\text{ (correct to 3 decimal places)} \end{gathered}[/tex]