SOLUTION: A university test was given where the scores are normally distributed. A student had a score of 61% which was 2.45 standard deviations from the mean. If the mean of the exam scor

Algebra ->  Probability-and-statistics -> SOLUTION: A university test was given where the scores are normally distributed. A student had a score of 61% which was 2.45 standard deviations from the mean. If the mean of the exam scor      Log On


   



Question 25143: A university test was given where the scores are normally distributed. A student had a score of 61% which was 2.45 standard deviations from the mean. If the mean of the exam scores was 54%, then what was the standard deviation of the exam scores?
And I would like to say thank you to everybody who answered all my problems in the past and to the person who solves this question.

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
Use the "z" formula:
z(x)=(x-mu)/sigma
2.45 = (0.61-0.54)/sigma
sigma = (0.07)/2.45 = 0.02857...
Cheers,
Stan H.