Question

The variables x and y are related proportionaly. when x=4,y=10 find y when x =18when x=18,y=_____

Answer 1

For variables to be related proportionally, the relationship must have a constant of proportionality. In our case we will represent the constant of proportionality as k. Therefore,

`\begin{gathered} y=kx \\ \text{where} \\ k=\text{constant of proportionality} \\ 10=4k \\ k=(10)/(4) \\ k=(5)/(2) \end{gathered}`

Now lets find y when x = 18

`\begin{gathered} y=kx \\ y=(5)/(2)*18 \\ y=(90)/(2) \\ y=45 \end{gathered}`