$x, y, z$ are three numbers. The mean of $x, y, z$ is $3x$. What is the mean of $y$ and $z$?
Is the answer $4x$?
$x, y, z$ are three numbers. The mean of $x, y, z$ is $3x$. What is the mean of $y$ and $z$?
Is the answer $4x$?
Yes. Simply write: $ \frac{x+y+z}{3} = 3x\Rightarrow y+z = 8x\Rightarrow \frac{y+z}{2} = 4x. $
If the mean of three numbers is $3x$, then the sum of the numbers is $9x$. ...