Plan from the supplied facts
Ten fictional comparable observations are 2,2,3,3,4,4,5,6,8,10 hours. This worksheet defines its eight-in-ten threshold as the eighth value after sorting ascending. It describes this finite sample only and makes no future probability claim.
| Sorted positions | Hours | Cumulative observations |
|---|---|---|
| 1–4 | 2,2,3,3 | 4 |
| 5–8 | 4,4,5,6 | 8 |
| 9–10 | 8,10 | 10 |
Work through the choice
The selected eighth value is 6, and exactly eight supplied observations are no greater than 6. Other interpolation methods could give a different statistic, so retain this explicit local order rule.
Under the same local rule, what is the nine-in-ten threshold?
Show the worked answer
The ninth sorted value is 8 hours. This is a sample threshold, not a 90% delivery guarantee.
Material to use in your plan
Keep the full sorted observations, the chosen rank and the selected value. Name the finite-sample rule in the plan and do not attach future confidence without separate evidence.