What are the coordinates of vertex j of the pre-image? (0, -4) (0, -1) (0, 0) (0, 4)

Bit late for you, but for people from the future it's (0,-4).

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.