Median:
1. Order the data from less to greater:
4.4
5
5.2
5.7
14.9
18.8
2. As it is a even number of data you take the average of the two data in the middle to find the median:
[tex]\frac{5.2+5.7}{2}=5.45[/tex]The median is 5.45Standard deviation formula (for a sample):
[tex]s=\sqrt{\frac{\Sigma(x_i-\bar{x})\placeholder{⬚}^2}{n-1}}[/tex]To find the standard deviation of the given data:
1. Find the difference between each data and the mean:
[tex]\begin{gathered} (x_i-\bar{x}) \\ \\ 5.2-9=-3.8 \\ 18.8-9=9.8 \\ 5.7-9=-3.3 \\ 5-9=-4 \\ 14.9-9=5.9 \\ 4.4-9=-4.6 \end{gathered}[/tex]2. Find the square of each difference:
[tex]\begin{gathered} (x_i-\bar{x})\placeholder{⬚}^2 \\ \\ (-3.8)\placeholder{⬚}^2=14.44 \\ (9.8)\placeholder{⬚}^2=96.04 \\ (-3.3)\placeholder{⬚}^2=10.89 \\ (-4)\placeholder{⬚}^2=16 \\ (5.9)\placeholder{⬚}^2=34.81 \\ (-4.6)\placeholder{⬚}^2=21.16 \end{gathered}[/tex]3. Find the sum of the squares:
[tex]\begin{gathered} \Sigma(x_i-\bar{x})\placeholder{⬚}^2 \\ \\ 14.44+96.04+10.89+16+34.81+21.16=193.34 \end{gathered}[/tex]4. Use the formula of the standard deviation for n=6:
[tex]s=\sqrt{\frac{193.34}{6-1}}=\sqrt{\frac{193.34}{5}}=\sqrt{38.668}\approx6.22[/tex]Then, the standard deviation is 6.22