Write the following algebraic notation, using the letter x for any unknow numbers:
I think of a number, double it ,then add fifteen

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.