A lab group was measuring the mass of an object. They recorded the following masses for the same object: 12.13 g, 12.12 g, 12.13 g, and 12.11 g. The actual mass of the object was 17.13 g. Which of the following best describes the lab groups results? The results were both accurate and precise. The results were accurate but not precise. The results were precise but not accurate. The results lacked both precision and accuracy.

Precise, but not accurate

Explanation:

First, let’s define accuracy and precision.

⇒Accuracy: how close you are to the actual value

⇒Precision: how close the measurements are to each other.

Let’s examine the data given:  

12.13 g, 12.12 g, 12.13 g, and 12.11 g

Each number is or is very close to 12.12 (within 0.1)

The actual mass of the object is 17.13 grams. Each measurement is about 5 grams away from the actual mass.

Since the measurements are very close to each other, but quite far from the true value, we can say the results are precise, but not accurate.

a:

by the combination of an unlimited number of elements