Answers:
a) mean = 2
b) Standard Deviation = 5.77
c) Probability that it takes 30 minutes for the next train to arrive = 0.75
d) Probability that the time taken will be between 25 and 30 minutes = 0.25
e) The 80th percentile = 31 minutes
f) The third quartile = 30 minutes
Explanations:
Check the attached files for the solvings