The mean is given by:
[tex]\begin{gathered} \mu=\frac{23.8+17+29.1+28+15.3+6.8+29.3+16.8+1.3+21.3}{10} \\ so: \\ \mu=\frac{188.7}{10} \\ \mu=18.87 \end{gathered}[/tex]The median is:
[tex]{}{}\lbrace1.3,6.8,15.3,16.8,17,21.3,23.8,28,29.1,29.3\rbrace[/tex]The median is the middle number in a list of values, first we had to sort the list in increasing order. Since we have an even number of values we have to average the middle two numbers, so:
[tex]Me=\frac{17+21.3}{2}=\frac{38.3}{2}=19.15[/tex]Finally, the standard deviation is:
[tex]\begin{gathered} \sigma=\sqrt{\frac{1}{N}\sum_{n\mathop{=}1}^N(x_i-\mu)^2} \\ so: \\ \sigma=\sqrt{\frac{1}{10}\sum_{n\mathop{=}1}^{10}(x_i-18.87)^2} \\ \\ \sigma=\sqrt{80.1921} \\ \sigma\approx8.9550 \end{gathered}[/tex]