If y varies directly as x and z and y=4 when x=6 and z=1 find y when x=7 and z=4

Step-by-step explanation:

We have been given that y varies directly as x and z.

We know that equation of two directly proportional quantities is in form , where, k is constant of proportionality.

Since y varies directly as x and z, so our equation would be

We are also told that , and . Let us find constant of proportionality as:

Now, we will solve for y by substituting , and

Therefore, .