Assuming the trend that exists in the data set below applies to all students, how long should Trevor study if he want to get at least a 75% on the test?

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.