Question 315513
The mean for a set of 28 scores is 80. Suppose two more students take the test and score 60 and 50. What is the new mean?
<pre><b>
{{{AVERAGE = (SUM_OF_SCORES)/(NUMBER_OF_STUDENTS)}}}

When there are 28 students,

{{{80=(SUM_OF_SCORES)/28}}}

Multiply both sides by 28:

2240 = SUM_OF_SCORES

Now after those two extra students take the test,
the new sum of scores will be 2240 + 60 + 50 = 2350,
and the number of students will be 28 + 2 = 30 

Using the formula again:

{{{AVERAGE = (SUM_OF_SCORES)/(NUMBER_OF_STUDENTS)}}}

{{{AVERAGE = 2350/30=78&1/3}}}

Edwin</pre>