6.5.10 - Compound percentage uncertainties

Combine percentage uncertainties correctly.

Use - compound percentage uncertainties to connect the rule to the data and decision in the question.

This matters because - compound percentage uncertainties determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply - compound percentage uncertainties to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: - Compound percentage uncertainties is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.