9)
The mean of the data set was correctly calculated (mean=16).
MAD stands for median absolute deviation and its formula is
[tex]\begin{gathered} MAD=\frac{\sum_i^{\text{ }}|x_i-mean|}{N} \\ N\rightarrow\text{ number of elements in the data set} \end{gathered}[/tex]
Thus, in our case,
[tex]\begin{gathered} MAD=\frac{1}{10}(|13-16|+|14-16|+...+|18-16|+|19-16|)=\frac{1}{10}(3+2+2+0+0+0+0+2+2+3) \\ \Rightarrow MAD=\frac{1}{10}(14)=1.4 \end{gathered}[/tex]
Hence, the MAD of the data set is 1.4
