What is the mean and median of 7, 9, 12, 9, 13?
Let's first order the numbers in ascending order. We now have
The mean is the average of our data set. We sum up our numbers, and divide by how many numbers there are. We have
The red expression is the sum of our data, and the blue is how many numbers we have. We find that the mean is
The word "median" literally means the middle of something. In this case, it is the middle number in our data set.
The middle number is
Hope this helps!