Answer:
the median is 6.
Please see the picture attached.
A line plot shows the number of occurrences (crosses) of each number of a data set.
The median is the central value, the middle number, of a data set ordered from least to greatest. When there are two middle numbers, the median will be the mean between the two.
In order to find the median, look at the line plot: count how many values you have (22), then add 1 (23) and divide by two (11.5). Since we have an even number of values, we will have two middle numbers, which will be in the eleventh and twelfth position.
Count the crosses from the left, the eleventh and twelfth crosses both correspond to the number 6, therefore
the median is 6.
You can also write all the numbers in increasing order and divide them into two equal groups:
1, 2, 3, 3, 4, 4, 5, 5, 5, 6, 6 | 6, 6, 7, 7, 7, 8, 8, 8, 9, 9, 11
The median will be the average between the two central numbers, therefore
6 (again).