The median is not the same as the mean (which is usually average).
The mean is the sum of all data divided by the number of data. So, the mean of these numbers would be 0.94:
(1 + 0.5 + 0.3 + 0 + 0 + 0 + 1.2 + 3 + 0 + 1.1 + 0.7 + 2 + 1.3 + 2)/14 = 13.1/14 = 0.94

But we need the median which is the middle value. To find the median, first rearrange the data from the lowest to the highest value. If there is an odd number of data, then the median is the value in the middle. If there is an even number of data, then the median is the mean of the two values that are in the middle.
Calculation of the median:
Step 1. Rearrange the data from the lowest to the highest value.
0, 0, 0, 0, 0.3, 0.5, 0.7, 1, 1.1, 1.2, 1.3, 2, 2, 3
Step 2. Since zhere is the even number of data, find two values in the middle and calculate their mean:
0, 0, 0, 0, 0.3, 0.5, 0.7, 1, 1.1, 1.2, 1.3, 2, 2, 3
7th and 8th values are in the middle. There mean is:
(0.7 + 1)/2 = 1.7/2 = 0.85

Therefore, the median of the data  1, 0.5, 0.3, 0, 0 ,0, 1.2, 3, 0, 1.1, 0.7, 2, 1.3, 2 is 0.85.