Question 215199
Sandy's average for three tests is 84.  What must she earn on the next test to raise her average to 88?


Step 1.  Let x be the next score to average 88.


Step 2.  Since the average is 84 for three tests, let's just say the scores be 84 for all three tests.


{{{(84+84+84+x)/4=88}}}


{{{252+x=88*4=352}}}


{{{252+x-252=352-252=100}}}


{{{x=100}}}



Check...{{{(84+84+84+100)/4=88}}} or {{{88=88}}} which is a true statement.


Step 3.  The next test score is 100 to average 88.  


I hope the above steps were helpful.


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Good luck in your studies!


Respectfully,
Dr J