Answer:
Precise means getting the same result (e.g., number) each time in a series of replicating experiments. Accurate means that the result is very close to the actual number. One can have a precise, but inaccurate result. Precision does not preclude systemic errors. On the other hand, accurate data may look sloppy, but it produced a correct result.
Step-by-step explanation:
Let's image an experiment in which the actual value is know to be 5.
Precise:
Now say you and your lab-mate got the following results after 6 measurements of the same experiment.
Precise Accurate
4.5 6.5
4.4 4.1
4.6 5.1
4.5 5.1
4.5 5.8
4.6 3.5
Total 27.1 30.1
Avg. 4.52 5.02
The precise readings are closer together than the accurate readings, but they are not as accurate (4.52) as the sloppier, but more accurate measurements on the right, which show an average value of 5.02, very close to the actual value of 5. Thus, one can have results that are very precise (the numbers are all close to each other), but still wind up with an inaccurate number. This is often due to some constant error, perhaps a mis-calibrated instrument or improperly made solution. The series of measurements under Accurate, show greater deviation from each other, but the average, 5.02, is very close to the actual value, 5.0.