Which combination describes measurements that are not accurate but are precise?

Which combination describes measurements that are not accurate but are precise?

• A. Accurate, precise
• B. Not accurate, precise
• C. Not accurate, not precise
• D. Accurate, not precise

Answer: (B)

Understanding measurements, accuracy is how close your results are to the true value, while precision is how close the results are to each other. If every measurement lands near the same value but that value is away from the true value, you’re precise but not accurate. For example, a scale that consistently reads 2 units low will produce tightly clustered results around that wrong value. That’s not accurate, but precise. In contrast, if readings vary widely around the true value, they are accurate on average but not precise; if they’re tightly grouped but far from the true value, that’s not accurate but precise; and if they’re both tight and correct, that’s accurate and precise. So “not accurate, precise” best describes measurements that are consistently off from the true value but highly repeatable.

Understanding measurements, accuracy is how close your results are to the true value, while precision is how close the results are to each other. If every measurement lands near the same value but that value is away from the true value, you’re precise but not accurate. For example, a scale that consistently reads 2 units low will produce tightly clustered results around that wrong value. That’s not accurate, but precise.

In contrast, if readings vary widely around the true value, they are accurate on average but not precise; if they’re tightly grouped but far from the true value, that’s not accurate but precise; and if they’re both tight and correct, that’s accurate and precise. So “not accurate, precise” best describes measurements that are consistently off from the true value but highly repeatable.