Question 485561
<pre>
Let x be the missing score.

{{{mean=(sum_of_scores)/(number_of_scores)}}}

{{{79.5=(82+71+83+91+78+x)/6}}}

{{{79.5=(405+x)/6}}}

Multiply both sides by 6

{{{477=405+x}}}

{{{477-405=x}}}

{{{72=x}}}

So she made a 72 on it.

Edwin</pre>