Description
3. The scores on a university examination are normally distributed with a mean of 62 and a standard deviation of 11. If the bottom 5% of students will fail the course, what is the lowest mark that a student can have and still be awarded a passing grade?
a) 62 b) 57 c) 44 d) 40
Explanation & Answer
Using a standard normal probabilities table (probably at the back of your textbook), 5% or 0.0495 approximately has a z-score of -1.65.
x=xbar(mean) + z*σ
x=62+ (-1.65)(11)
x=43.85
x=44
So the lowest mark that a student can have without failing is 44%.
answer= (c)=44