SOLUTION: The marks for a university class were normally distributed with a mean of 65% and a standard deviation of 20%. What is the probability that a student selected at random from the cl
Algebra ->
Statistics
-> Normal-probability
-> SOLUTION: The marks for a university class were normally distributed with a mean of 65% and a standard deviation of 20%. What is the probability that a student selected at random from the cl
Log On
Question 1170018: The marks for a university class were normally distributed with a mean of 65% and a standard deviation of 20%. What is the probability that a student selected at random from the class had a mark that was between 60% and 75%? Give your answer to four decimal places. Answer by Boreal(15235) (Show Source):
You can put this solution on YOUR website! z=(x-mean)/sd
so z (0.60) is (60-65)/20 or -0.25
and z(0.75) is +0.5
The probability of z between those two values is 0.2902
