Find the median of the following data: 9, 6, 12, 5, 17, 3, 9, 5, 10, 2, 8, 7

Step 1: Definition of the median
Median:
The median of a set of data is the middlemost number in the set.
The median is also the number that is halfway into the set.
let's say n is the number of observations
If n is odd, The median = \frac{n+1}{2}th term
If n is even, The median = \frac{\frac{n}{2}+\left(\frac{n}{2}+1\right)}{2}
Step 2: Arrange the data in either ascending order or descending order
GIVEN: 9, 6, 12, 5, 17, 3, 9, 5, 10, 2, 8, 7
Ascending order
2, 3, 5, 5, 6, 7, 8, 9, 9, 10, 12, 17
Step 3: Count the number of observations and find the median of the given data
There are 12 observations
n = 7 is a even number
There is an even number of numbers, so there are two numbers in the middle.
The median is the mean of the two middle numbers.
So, the median = \frac{\frac{n}{2}+\left(\frac{n}{2}+1\right)}{2}=\frac{\frac{12}{2}+\left(\frac{12}{2}+1\right)}{2}=\ \frac{6^{th}\ term+\ 7^{th}\ \ term}{2}
Median = \frac{7 + 8}{2}
= \frac{15}{2}
Hence, the median = 7.5