I think C. Am I correct?

The grades on the last art exam had a mean of 75%. Assume the population of grades on art exams is known to be distributed normally, with a standard deviation of 7%. Approximately what percent of students earn a score between 75% and 82%?
37.2%
84.1%
34.1%

Question

I think C. Am I correct?

The grades on the last art exam had a mean of 75%. Assume the population of grades on art exams is known to be distributed normally, with a standard deviation of 7%. Approximately what percent of students earn a score between 75% and 82%?
37.2%
84.1%
34.1% <---- 
50%

vladthepro · Answer

@mathstudent55  @agent0smith  Am I correct?

roxy.girl · Answer

mean of 75%.
standard deviation of 7%

score between 75% and 82%?

(it is a bit confusing because our measurements are percents (on a test)... and we also have percent (under a curve) )

but we want the area under the bell curve from 75% (the mean)  and 82% (which is 1 std dev to the right of the curve)

how much area is between the mean and 1 std dev from the mean
do you know how to figure that out ?

agent0smith · Answer

http://www.regentsprep.org/regents/math/algtrig/ats2/normal67.gif 19.1 + 15 = 34.1%

vladthepro · Answer

Thx  for ur time and help :)

agent0smith · Answer

You're welcome