What number should be added to the expression x^2+4x to change it into a perfect square trinomial?

1

2

4

8

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.