Which statement about critical chain methodology is best?
1) Activity durations estimated at a 50% level of successful completion are shorter than those estimated at a 90% level of successful completion.
2) Aggregated activity durations at a 90% level of successful completion are shorter than aggregated activity durations at a 50% level of successful completion.
3) The total safety buffer for aggregated activity durations is smaller than the sum of safety buffers for individual activity durations at any likelihood level estimate.