Answer:
The product of (k + 1) series starts with 3 (because k = 2) and you need 2 to be multiplied to this in order to get (n + 1)!
Therefore you need to multiply 2 and 1/2 to make it right. 2 completes the factorial and 1/2 remains.
Hope it was clear explanation.

For unorganized data, median is the middle value when the numbers are arranged in ascending order.
Let's proceed ~
In ascending order :
12, 13, 23, 26, 26, 35, 38, 44, 47
So, for given data... median is 26