There are x ducks in a pond. the number of swans in the pond is equal to the square root of the number of ducks. if the total number of swans and ducks in the pond is 12, find the number of ducks.

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.