So I'm working through this and got to the section about the PERT formula, which states: O = Optimistic, everything goes smoothly; example: Maria already has a template. No rewrites needed. Maybe 2 hours. M = Most likely, normal day, few edits, nothing wild; example: She drafts, gets quick feedback, tweaks it. Maybe 4 hours. P = Delays and hiccups happen; example: Stakeholder changes direction twice, big rewrites. Maybe 7 hours. so using the PERT formula Expected = (O + 4M + P) ÷ 6 - Optimistic O = 2 hours - Most likely M = 4 hours - Pessimistic P = 7 hours If we plug in those numbers, it becomes: Expected = (2 + 4·4 + 7) ÷ 6 This is the part where we go back to middle school math and reuse PEMDAS (also known as GEMS, GEMA, BODMAS & BIDMAS) but to be simple it's our order of operations! First solve in your bracket or parenthesis, keeping order, so move onto your multiplication first. 4x4 = 16, now you're left with (2+16+7) ÷ 6 Finish off your parenthesis then move on to division, (25) ÷ 6 This is going to give us a rounding decimal, and at the end we'll have roughly E = 4.17 hours as the "most likely" estimate. *Some information has been requested so I'm going to be adding to this a little bit! * When working with the PERT formula, as seen above it is written as (O+4M+P) ÷ 6, let's expand a little on that and why we have the 4 & 6 within our forumla! Within the PERT formula the 4 & 6 are included to create a weighted average, not a regular average. Our "most likely" metric is mulitplied by 4 because PERT assumes the "most likely" outcome should matter more than the extreme outcomes. A normal average of the three estimates would be O+M+P÷3 but this treats the three metrics as *equally important* and for real projects that isn't realistic. Our most likely estimate is usualyl more representative than the "everything goes perfectly" or "everything goes wrong" scenarios. This is why PERT give the most likely estimate extra weight by counting it four times.