Problem:
Compute the mean of ${0, -\frac{9}{\sqrt{5}}, -\frac{12}{\sqrt{5}}, 3 \sqrt{5}, -\frac{16}{\sqrt{5}}}$.
Answer:
$\frac{1}{5} \left(3 \sqrt{5}-\frac{37}{\sqrt{5}}\right)$
{'source': 'AMPS', 'file': 'amps/mathematica/counting_and_statistics/mean/10673.txt'}