In order to find the median of the number of pencils, first order the information of the dot-plot graph:
1 1 1 2 2 2 2 3 3 5
there are ten data, the median is one half the sum of the two data at the center of the list:
1 1 1 2 2 2 2 3 3 5
(2 + 2)/2 = 4/2 = 2
Hence, the median is 2