Abag contains 50 marbles,10 of which are blue ,8 are red,20 are green ,and 12 are purple . marcie takes a ow marble out of the bag ,records the color and returns
it to the bag how many red marbles should she expect after 500 trials

After 500 trials, she should expect 0.16 * 500, or 80 red marbles. 0.16 is the frequency of red (8/50). If you extend this expected frequency to 500 trials, it will be 80.

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.