# Question #6dc15

May 1, 2015

They are neither accurate nor precise.

#### Explanation:

Precision refers to how close your measurements are to one another.

Accuracy refers to how close your measurements are to what they should be.

Imagine a dartboard. You have four darts. Several scenarios can play out:

$$  1.  All four darts land very close to one another but far away from the bullseye.  Precise, yes....accurate, no.

2. All four darts land away from one another and far from the bullseye.  Precise, no....accurate no.

3.  A couple of darts land in the bullseye and a couple surrounding the bullseye. Precise, not so much....accurate, yes

4.  All four darts land in the bullseye.  Precise, yes....accurate,    yes.


The average of your measurements is 2.3 ± 0.2.

The true value is 3.1. This is well beyond your average value, so your measurements are not accurate.

You are measuring with an uncertainty of ± 0.1 unit.

Your measurements would be precise if they ranged from 2.2 to 2.4.

Half of your measurements are outside this range, so your measurements are not precise.

Hope this helps.