A bag contains 10 marbles: 2 are green, 2 are red, and 6 are blue. Yolanda chooses a marble at random, and without putting it back, choose another one at random. What is the probability that both marbles she chooses are green? Write your answer as fraction in simplest form.

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.