- #1
semidevil
- 157
- 2
Homework Statement
Test scores are normally distributed. The mode of the score is 55%. If 75% of the students scored 65, what % of student scored 85?
2. Homework Equations and attempt at solution
Scores being normally distributed, I know that as the 'bell curve (that means the curve is distributed with mean 0, variance 1).'
I also know 'mode' is the peak of the bell curve, since mode is the most people who scored a 55.
I really don't know where and how to proceed from there.
25% of the students scored 65, I can do (x - 65)/ standard deviation = .25% (or phi .68). I get x = 65.68 students.
So around 66 of students scored 65...right?
What's the next step? I don't know how to use the mode in this problem.