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$x, y, z$ are three numbers. The mean of $x, y, z$ is $3x$. What is the mean of $y$ and $z$?

Is the answer $4x$?

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    If $\dfrac{x+y+z}{3}=3x$, then...2011-10-25

2 Answers 2

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Yes. Simply write: $ \frac{x+y+z}{3} = 3x\Rightarrow y+z = 8x\Rightarrow \frac{y+z}{2} = 4x. $

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If the mean of three numbers is $3x$, then the sum of the numbers is $9x$. ...

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    This answer is useful.2011-10-25