Posted by Cherie on Friday, May 4, 2012 at 11:59am.
A student got these marks on 7math tests:
91%,75%,95%,,80%,83%,86%,68%
What mark will the student need on the 8th test to make each statement true?
a)The mean of the tests is 84%
b)The mode of the eight tests is 86%
c)The median of the eight tests is 84%

Math  PsyDAG, Sunday, May 6, 2012 at 4:23am
This should help you:
Mean = Σscores/number of scores = (All the scores +8th)/8
Mode is the most frequently occurring score.
Median is 50th percentile, so you need as many score below 84% as above. 
Math  Anonymous, Sunday, August 19, 2012 at 3:43pm
A student has a mean score of 88 on five tests taken. What score must she obtain on her next test to have a mean (average) score of 80 on all six tests?