Postal letter carrier has the route comprising of five segments with time in minutes to complete each segment being normally distributed with mean and variance as shown
Tennyson Place N (38,16)
Windsor Parkway N (99,29)
Knob Hill Apartments N (85,25)
Evergreen Drive N (73,20)
Chastain Shopping Center N (52,12)
Additionally to above times, letter carrier should organize mail at central office, which needs time which is distributed by N (90,25). Drive to starting point of route needs time which is distributed N (10,4). Return from route needs a time that is distributed N (15,4). Letter carrier then performs administrative tasks with time that is distributed N (30,9).
Overtime happens after eight hours of work on given day. Determine the probability that letter carrier works overtime on any given day? Determine the probability that route will be completed within +/-24 minutes of eight hours on any given day?