Question

The marks of the students in a class are normally distributed with mean 70 and S.D. of 5. If the

instructor decides to give grade ‘A’ to the top 15% of the class, how many marks a student must get

to be able to get ‘A’ grade?​

Answer 1

Answer:

Using the normal distribution, the probability that a random sample of 40 students is above 75 is approximately 1 − P(z < 3.16) = 1 − 0.9992 = 0.0008.