Question 402971
The sum of the x students test scores is {{{74x}}} since dividing this by 'x' students gives you an average of 74. Likewise, the sum of the y students test scores is {{{88y}}}



So because the "combined the average is 76", we know that {{{(74x+88y)/(x+y)=76}}} (ie add the sums of both groups and divide that new bigger sum by the total number of students x+y)



I'll let you take it from here. Since there is an explicit relationship between x and y (shown in the equation above), you can solve for either variable and substitute it into {{{x/y}}} and reduce it into some constant number. Note: either variable you solve for will give you the same answer.



Let me know if you still need help.