Gina has two job offers as a dog walker. She wants to earn at least $75 each week. The first offer pays $15 each week plus $3 per dog walked. Let x represent the number of dogs walked.

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.