Question

3. A teacher states that her grading policy on the course grade is as follows: Grade A: students whose score is more than 1.5 standard deviations above the mean Grade B: students whose score between 0.5 and 1.5 standard deviations above the mean Grade C: students whose score is within 0.5 standard deviations either side of the mean Grade D: students whose score is more than 0.5 standard deviations below the mean Assume that the course grade scores are normally distributed.

a. What percentage of A’s B’s C’s and D’s does she give?

b. If the test that the teacher is using has a mean of 55 and a standard deviation of 10, what are the test scores corresponding to the teacher’s cut scores?

Answer 1