SOLUTION: 1(a) David scored 82, 74 and 90 in three tests. What mark should he score in the fourth test so that his average marks for the four test would be 85%? (b) What was his median sc

Question 886548: 1(a) David scored 82, 74 and 90 in three tests. What mark should he score in the fourth test so
that his average marks for the four test would be 85%?
(b) What was his median score in the test?
Answer by JulietG(1812) (Show Source): You can put this solution on YOUR website!
David wants 85% in four tests, or 340/40
So far, he has 82+74+90, or 246 points.
340 - 246 = 94
.
If he scores 94, his scores will be 74, 82, 90, 94
The median is the middle number. In this case we have TWO middle numbers: 82 and 90. Add them together and divide by 2 to find the median.
82 + 90 = 172
172 /2 = 86
The mean is 85 (that was a given from earlier)
As for mode, each number occurs only once. We *could* say that they are all the mode or none the mode. Grouping is a better solution, though. There is one value in the 70s, one in the 80s, and two in the 90s, so "90s" would be the mode.
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