A professor at the Northern Caribbean University found that the Principles of Psychology exam scores was normally distributed with mean ()= 65 and the score at the point of inflection = 75, among the population of 3,000 students.

Using the information above answer all of the following questions, Q1 to Q5:

Q1. What is the standard deviation () equal to?

Q2. What is the proportion of scores that fall between 65 and 75?

Q3. What is the percentage of scores that fall below 67?

Q4. How many of the 3,000 scores fall above 85?

Q5. What proportion of the scores fall above 85?