The scores on a final exam were approximately normally distributed with a mean of 82 and a standard deviation of 11. If 85 students took the exam, and above a 60 is a passing grade, how many students failed the exam?

A. 13
B. 1
C. 2
D. 12

Question

The scores on a final exam were approximately normally distributed with a mean of 82 and a standard deviation of 11. If 85 students took the exam, and above a 60 is a passing grade, how many students failed the exam?
 
A. 13 
B. 1 
C. 2 
D. 12

amistre64 · Answer

any ideas how to process th einformation?

anonymous · Answer

I know it's not D. Maybe A?

amistre64 · Answer

82 - 60 = 22

and there are 22/11 = 2 standard devitaions to assess the situation with

amistre64 · Answer

since 95% of the data falls within 2 sd of the mean ... that leaves about 5% to split between that tails.

so about 2.5% of the students are expected to fail.

anonymous · Answer

Answer is C then right?

amistre64 · Answer

yeah, im getting about 2 out of 82 that is expected to get 60 or lower