A project manager is estimating activity durations for a project. Which of the following should he or she consider while performing this activity?

While calculating the duration of schedule activities, differences in the capabilities of staff assigned should not be taken into consideration. All senior and junior staff should be given equal weight.

While calculating the duration of schedule activities, differences in staff capabilities should be taken into consideration. A senior staff member will generally be expected to finish an activity in 80 percent of the time that a junior member.

While calculating the duration of schedule activities, differences in staff capabilities should be taken into consideration. A senior staff member will generally be expected to finish an activity in less time than a junior member.

While calculating the duration of schedule activities, an average should be used and the actual differences in the capabilities of staff assigned should not be taken into consideration.