What is the shape of the following distribution? {9, 10, 10, 11, 11, 12, 12, 13, 13, 13, 14, 14, 14, 14, 15, 15, 15, 15, 16, 16, 16, 16, 17, 17, 17, 17, 18, 19, 20}

The shape of the distribution with the following data set you gave is skewed to the left or negatively skewed. This is because the frequency of each number increases as its value increases. 

I'm not sure exactly but my best guess would be 1/4