If an order is for 500mg from a dosage strength of 250 mg/mL, is to be administered in 20 cc D5 1/2NS, how many mL of drug is used and how many mL of D5 1/2NS is used?

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.