Question 1193247: Erika’s teacher summarized the achievement test results of her class in the table below. If Erika belongs to this class and her score is 76, does she belong to the upper 25% of her class? Justify your answer.
Score f
90-99 3
80-89 4
70-79 6
60-69 11
50-59 8
40-49 5
30-39 3
Answer by math_tutor2020(3817)   (Show Source):
You can put this solution on YOUR website!
Add up all the scores in the column labeled "f"
3+4+6+11+8+5+3 = 40
There are 40 students total in the class.
The group 90-99 represents the top 3 students
3/40 = 0.075 = 7.5%
Meaning that students in this group are the top 7.5% of the class.
In other words, 7.5% of the scores are 90 or above, while the bottom 92.5% scores are 30 through 89.
The first two groups combine to 3+4 = 7 students
They represent the top 7/40 = 0.175 = 17.5% of the class
The first three groups combine to 3+4+6 = 13 students
They represent the top 13/40 = 0.325 = 32.5% of the class
It's fairly clear that 25% is between 17.5% and 32.5%, which indicates that it's possible that the score of 76 represents the cut off point between the top 25% and the bottom 75%
However, there isn't a full guarantee because the 25th percentile marker may be another value in the interval 70-79
Answer: It's possible, but we don't have enough info to guarantee it.
|
|
|
