Question

The grade-point average in an econometrics examination was normally distributed with a mean of 75. In a sample of 10 percent of students it was found that the grade-point average was greater than 80. Can you tell what the s.d. of the grade-point average was?

Answer 1

To solve a standard deviation we require a specific result for each data. So this question(data from question) can not be enough to solve standard deviation.