Posted by Math(: on Wednesday, March 30, 2011 at 10:05pm.
John has scores of 88,73,90,85,93 on five math quizzes. What scores must john earn on the next math quiz to have a mean quiz score of exactly 88?

Math  Compstudent, Wednesday, March 30, 2011 at 10:31pm
The mean means:
Add all numbers and then divide how many numbers there are
First Step:
88 + 73 + 90 + 85 + 93 = 429
Second Step:
429 / 5 = 85.8 < that is the mean of what you got.
However, the question asks you for what future grade you must make on the next test to average an 88% with those current grades. So this will tell us that we have to make at least in the 90's.
So we try 99%
88 + 73 + 90 + 85 + 93 + '99' = 528
then again we must divide by amount of numbers. Which there are 6 now, instead of 5.
528 / 6 = 88
So, in order for a student to receive an average of an 88%, they must make a 99% on the next test.
Cheers!

Math  Anonymous, Thursday, April 7, 2011 at 3:46pm
Johns next quizz will be 6th.
If He want 88 points in tis case must be:
(88+73+90+85+93+x)/6=88
88+73+90+85+93+x=88*6
429+x=528
x=528429
x=99
(88+73+90+85+93+99)/6= 528/6 = 88
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