(adsbygoogle = window.adsbygoogle || []).push({}); a formula used in project management for determining the expected time of an activity states that:

Expected time = (Pessimistic value + 4*most likely value + Optimistic value)/6

I am searching for a proof for this law. I've searched the internet, and found out it's related to the Beta Distribution function, but little details about how the shape parameters of the beta distribution were chosen and why?

Can someone explain to me the outline of the proof at least?

Thanks in advance.

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# PERT formula proof?

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