The table below shows the scores of a group of students on a 10-point quiz. Test score | Frequency
3 | 0
4 | 1
5 | 1
6 | 3
7 | 6
8 | 2
9 | 1
10 | 0

The mean score on this test is?
The median score on this test is?

The major difference is that a histogram is only used to plot the frequency of score occurrences in a continuous data set that has been divided into classes, called bins.  bar charts, on the other hand, can be used for a great deal of other types ofvariables  including  ordinal  andnominal  data sets.