Question

The following measurements were made to determine the density of a material whose value was, according to the Handbook of Chemistry and Physics, 1.24 g/mL Trial #1 1.24 g/mL Trial #2 1.22 g/mL Trial #3 1.22 g/mL

What general statement can be made on the accuracy and the precision of these results. Click on all that apply (2 points)


1.These results are accurate because the collected data is very close to the actual value

2.These results are accurate because all three trials are within a very close range. 3.These results are precise because the collected data is very close to the actual value

4.These results are precise because all three trials are within a very close range. 5.These results are neither accurate nor precise.

Answer 1

1.These results are accurate because the collected data is very close to the actual value.

4.These results are precise because all three trials are within a very close range.

Explanation:

Although in the ordinary language the terms precision and accuracy may be confused, in science those terms refer different properties of the measurements.

The accuracy is how close a measurement is to the true value, while the the precision refers to the reproducibility and repeatability, this is how the results show the same (close) value.

To differentiate precision and accuracy, It is very illustrative, to use the image of a throwing arrows to a target: if the arrows get close to the center of the target, then the results are accurate (close to the goal). If the arrows are not close to the cener of the target, but they are all close to each other, then the result is precise (the arrows land, approximately, in the same spot every time).