4 A project is represented by the activity network below.
The activity durations are given in minutes.
\includegraphics[max width=\textwidth, alt={}, center]{6f64abca-108c-4b81-8ccf-124dfd9cc2f6-5_447_1020_392_246}
- Give the reason for the dummy activity from event (3) to event (4).
- Complete a forward pass to determine the minimum project completion time.
- By completing a backward pass, calculate the float for each activity.
- Determine the effect on the minimum project completion time if the duration of activity A changes from 2 minutes to 3 minutes.
The duration of activity C changes to \(m\) minutes, where \(m\) need not be an integer. This reduces the minimum project completion time.
- By considering the range of possible values of \(m\), determine the minimum project completion time, in terms of \(m\) where necessary.