Assume the length of time students take in writing a standard entrance examination is normally distributed with mean 60 minutes, std. deviation 8 minutes
(a) Find the probability that a randomly selected student takes between 60 and 70 minutes to write the exam.
(b) Find the probability that a randomly selected student takes at most 80 minutes to write the exam.
(c) If a randomly selected student has taken over 40 minutes, find the probability they will take at most 80 minutes to write the exam.
(d) Find the 50th percentile for the time it takes for students to write the exam.