Question

question
if the accepted value for a measurement is 60.3 ml, which of the following set of measurements is precise but not accurate?
select the correct answer below:
56.7 ml, 87.3 ml, 28.9 ml
60.2 ml, 60.3 ml, 60.1 ml
76.5 ml, 76.4 ml, 76.3 ml
all of the above

Explanation:

Step1: Define accuracy and precision

Accuracy: closeness to the accepted value (\(60.3\ \text{mL}\)). Precision: closeness of measurements to each other.

Step2: Analyze each option

• Option A: \(56.7\ \text{mL}, 87.3\ \text{mL}, 28.9\ \text{mL}\)

Measurements are neither close to \(60.3\ \text{mL}\) (not accurate) nor close to each other (not precise).

• Option B: \(60.2\ \text{mL}, 60.3\ \text{mL}, 60.1\ \text{mL}\)

Measurements are close to \(60.3\ \text{mL}\) (accurate) and close to each other (precise).

• Option C: \(76.5\ \text{mL}, 76.4\ \text{mL}, 76.3\ \text{mL}\)

Measurements are close to each other (precise) but not close to \(60.3\ \text{mL}\) (not accurate).

• Option D: all of the above

Since A is not precise and B is accurate, D is incorrect.

Answer:

C. \(76.5\ \text{mL}, 76.4\ \text{mL}, 76.3\ \text{mL}\)