The mean of the of the given set of numbers is calculated as;
[tex]\begin{gathered} M=\frac{\Sigma x}{x} \\ \text{Where M is the mean, }\Sigma x\text{ is the addition of all the numbers given,} \\ \text{And x is the number of data provided (7 in this case)} \\ M=\frac{\Sigma(12+15+3+13+9+6+11)}{7} \\ M=\frac{69}{7} \\ M=9.8571429 \\ M\approx9.86\text{ (rounded to two decimal places)} \\ \text{The median is the middle value, counting from both ends.} \\ \text{After arranging in ascending order, you now have} \\ 3,6,9,11,12,13,15 \\ \text{Taking thr}ee\text{ numbers from the left, and thr}ee\text{ numbers from the right,} \\ \text{The median (that is middle value) is 11.} \end{gathered}[/tex]
