SOLUTION: Student test grades were normally distributed, and grades between 62 and 86 were within three standard deviations of the mean. Find the mean and the standard deviation of the set o

Algebra ->  Probability-and-statistics -> SOLUTION: Student test grades were normally distributed, and grades between 62 and 86 were within three standard deviations of the mean. Find the mean and the standard deviation of the set o      Log On


   

Question 448468: Student test grades were normally distributed, and grades between 62 and 86 were within three standard deviations of the mean. Find the mean and the standard deviation of the set of grades.
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
 

Hi,

Student test grades were normally distributed

grades between 62 and 86 were within three standard deviations of the mean

   86-62 = 24   24/2 = 12 

Mean: 74       |62+12   or 84-12

SD = 4         |74 - 3*4 = 62  and 74 + 3*4 = 86