Find sample size for a target margin of error - exam scenario
A water authority wants margin of error at most 3 using \(\sigma=14\) and \(z=1.96\). Calculate the required sample-size expression before rounding up. Confirm the context meaning before entering the value. Enter the requested value and choose the interpretation that matches the result.
Worked practice: result and interpretation
Calculate the requested result first, then choose the interpretation that follows from it.
Write a full answer
Now write the response in full, in your own words — this is what the exam asks for. The AI marks it on the same moves you built above (focus, evidence, technique, judgement) and gives feedback on reasoning, evidence, and expression.