<PRE><B>Question 221123</B>
Suppose that the mean score of a class of 28 students was 74.
 The 18 male students in the class had a mean score of 66.
 What was the mean score for the 10 female students?
:
Let x = mean score of the girls
:
write a total score equation
boys + girls = total
18*66 + 10x = 28*74
:
1188 + 10x =  2072
:
10x = 2072 - 1188
:
10x = 884
x = {{{884/10}}}
x = 88.4 girls mean score</PRE>