Question

I need someone to check my answers to make sure that I have the correct answers. (3 Part Question)

Two students each measure the density of a quartz sample three times:

Student A Student B
3.20 g/mL 2.82 g/mL
2.58 g/mL 2.48 g/mL
2.10 g/mL 2.59 g/mL
mean 2.63 g/mL 2.63 g/mL

1. which student measured density with the greatest precision? explain your answer.
I think that student B, because their measurement where closest to each other.

2. which student measured density with the greatest accuracy? explain your answer.
I think it was student B as well, because their measurement was closest to the correct value.

3. Are the errors for these students random or systematic? Explain
I think that both students errors were random because each of these measurements were either higher or lower than the accepted value.

Please let me know if I am correct in my thinking.

thanking you in advance

Answer 1

I think you are right with #1. I can't answer 2 and 3 because I don't know the correct value.

Answer 2

Both student A and student B get a 100 for accuracy. If the correct value is 2.63 and both obtained 2.63 then both are about as accurate as you can get.

I would suggest that errors for both are random but I don't think you can tell that from the data. I think random errors are more likely to be "smaller" error but who is defining exactly what "smaller" means.