Find the mean deviation about the median for the following data:`3, 9, 5, 3, 12 , 10 , 18 , 4, 7, 19 , 21`.

Explanation

To find the mean deviation about the median for the given data set `3, 9, 5, 3, 12, 10, 18, 4, 7, 19, 21`, we will follow these steps:

### Step 1: Arrange the data in ascending order
First, we need to sort the data in ascending order.

**Sorted Data:**
3, 3, 4, 5, 7, 9, 10, 12, 18, 19, 21

...