Precision vs. Accuracy in Measurement Data

Steps:

• Assess precision by checking the spread of readings: tight clusters indicate high precision.
• Assess accuracy by checking the center of readings relative to true value V: clusters near V indicate high accuracy.
• From graphs, identify X and Y as precise (low spread) and Z as imprecise (wide spread).
• Determine X and Z as accurate (centered on V) and Y as inaccurate (offset from V).

Why D is correct:

• Definitions confirm two precise (X, Y with clustered data) and two accurate (X, Z near V), matching graph distributions.

Why the others are wrong:

• A: Undercounts accurate equipment; Z is also accurate.
• B: Undercounts both; Y is precise and Z is accurate.
• C: Overcounts precise; Y is precise but Z is not.

Final answer: D