Question 1154794
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<pre>

Let the numbers be "x", "y" and "z".


We are given that  {{{(x+y+z)/3}}} = a.


Hence,  x + y + z = 3a.


The new mean is   {{{(x + y + (z-9))/3}}} = {{{(x + y + z - 9)/3}}} = {{{(x + y + z)/3 - 3}}} = a - 3.    <U>ANSWER</U>
</pre>

Solved.


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On &nbsp;<U>Average</U> and &nbsp;<U>Mean</U>&nbsp; see the lessons 

&nbsp;&nbsp;&nbsp;&nbsp;- <A HREF=https://www.algebra.com/algebra/homework/Average/Solved-problems-on-average-scores-weight-height-and-temperature.lesson>Solved problems on average scores, weight, height and temperature</A>

&nbsp;&nbsp;&nbsp;&nbsp;- <A HREF=https://www.algebra.com/algebra/homework/Average/Solved-problems-on-average-scores.lesson>Solved problems on average scores</A>

&nbsp;&nbsp;&nbsp;&nbsp;- <A HREF=https://www.algebra.com/algebra/homework/Average/Solved-problems-on-average-age.lesson>Solved problems on average age</A> 

&nbsp;&nbsp;&nbsp;&nbsp;- <A HREF=https://www.algebra.com/algebra/homework/Average/Miscellaneous-problems-on-average-values.lesson>Miscellaneous problems on average values</A> 

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