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Challenge, difficulty 3 of 3

Moment skewness by hand

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Five patients' lengths of hospital stay (days) are 2, 4, 5, 6, 13.

Calculate the moment skewness $g_1 = m_3 / m_2^{3/2}$ , where $m_k$ is the average of the $k$ -th powers of the deviations from the mean (divide by $n$ ). Give it to 3 decimal places.