Question

Y varies jointly as x and z. y = 5.2 when x = 65 and z = 8. Find y when x = 55 and z = 10.

Answer 1

The value of y is 5.5

Explanation:

We have the following proportion

`y=k\cdot x\cdot y`

We can calculate the value of k, since we know the values of y, x and z.

Replacing and solving for k:

`\begin{gathered} 5.2=k\cdot65\cdot8 \\ k=(65\cdot8)/(5.2) \\ k=0.01 \end{gathered}`

Now, we calculate the value of y, just like that

`\begin{gathered} y=0.01\cdot55\cdot10 \\ y=5.5 \end{gathered}`