7. Bradley Park Hospital’s environmental services team wants to reduce patient room turnover times without sacrificing safety and room cleanliness. Their first task involves identifying all the activities necessary to clean and disinfect a room after patient discharge and their respective durations (in minutes). Their efforts led to the following network diagram.

a. What is the time estimate for each activity?

b. Find the ES, EF, LS, LF, and S for each activity and determine the critical path.
How long does it take to clean and disinfect a room?

c. What is the probability of completing the room cleaning and disinfection process in 65 minutes and in 75 minutes?

d. What is the probability that the process will take longer than 77 minutes?