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GATE 2017 CE (CE2) – Question 28

Construction Management · Project planning and scheduling: AOA and AON, PERT and CPM · 1 mark · Numerical answer

Project completion time is normally distributed with mean 200 days and standard deviation 6.1 days. The maximum completion time for 95% probability is ______ days. Use z = 1.64.

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Correct answer: 209 to 219

Explanation

Standardize completion time: $z=(T-200)/6.1$. Thus $T=200+1.64(6.1)=210.004$ days, approximately 210 days. This is the 95th-percentile completion time, not an absolute maximum of the unbounded normal distribution. The official accepted interval remains unchanged.