When Kendra had one cat, she needed to serve 1/6 of a can of cat food each day. Now that Kendra has adopted a second cat, she needs to serve a total of 1/2 of a can each day. How much extra food is needed to feed the second cat?

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.