Math
posted by Cherie .
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%

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. 
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?