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Question 930759: I am practicing means. Six students score a averaged 59 on a test. John was gone and scored a 84 on his "late test" including john what is the mean.
I tried this 84 times 6 - 59 times 6 and divided the difference by 7. I don't think I did that right though, So how do I do it?
Found 2 solutions by rcdodds, MathTherapy:
Answer by rcdodds(6)   (Show Source):
You can put this solution on YOUR website! The way to calculate an average is to add all the values and divide by the total number of values. Therefore, if the 6 students who took the test ontime averaged a 59, that means that 59 = (sum of scores) / 6.
From here we multiply both sides by six to find that the ontime test scores add up to 6*59 or 354.
But now along comes John to take his late test which isn't accounted for yet.
Well, now we have seven scores and to find their average we add them all up and divide by 7. But we only know one score from the problem, the 84 that John got late. Luckily, we know the other six scores add to 354, so adding John's score in we know that all seven scores add to 438. From here, we divide by 7 to get the average to be.....
Answer by MathTherapy(10557)  (Show Source):
You can put this solution on YOUR website! I am practicing means. Six students score a averaged 59 on a test. John was gone and scored a 84 on his "late test" including john what is the mean.
I tried this 84 times 6 - 59 times 6 and divided the difference by 7. I don't think I did that right though, So how do I do it?
Sum of the scores of 6 students: 6(59), or 354
Sum of the scores of 7 students, including John's: 354 + 84, or 438
Mean or average score of 7 students, including John's:  , or 
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