# Basic statistics question on outliers.

I have the following collection of data

$13,13,14,17,17,17,20,999$. I've calculated the mean, median and mode and am asked which measure of centre does not work well here (either of the 3 or none at all).

Now I can see that the mean is not a good measure here because of the $999$. But the median and mode are both $17$ which does seem to represent the centre well? I'm just confused as to whether the mean is the only thing that doesn't work well, or do none of them work well?

• suppose (for example) the numbers were estimates of the age of your neighbour's daughter, how confused need you be? – David Holden Apr 9 '18 at 11:54
• Ok so the median and mode would be good indicators as to the central estimates, yes? – moony Apr 9 '18 at 11:56
• Yes arithmetic mean is very sensitive to the presence of outliers, median and mode are mostly unaffected in that regard. – StubbornAtom Apr 9 '18 at 12:10
• Thank you. I'm happy to accept as an answer if you want to put it as an answer? – moony Apr 9 '18 at 12:11