Normal distribution & Probability 

The grades of a group of 5000 students in an exam are normally distributed with a mean of 75 and a standard deviation of 5. A student from this group is selected randomly.

(i) Find the probability that his/her grade is greater than 90.
(ii) Find the probability that his/her grade is less than 50.
(iii) Find the probability that his/her grade is between 50 and 75.
(iv) Approximately, how many students have grades greater than 75.

Answer

Answers can be viewed only if
  1. The questioner was satisfied and accepted the answer, or
  2. The answer was disputed, but the judge evaluated it as 100% correct.
View the answer
The answer is accepted.