Answer the following questions related to histograms:
(a) Distinguish between a histogram and a bar graph on any two points.
(b) Explain why the class intervals in a grouped frequency distribution must be continuous when you draw its histogram.
(c) The first class interval of a grouped data set is 20–29. Describe how you would show the horizontal axis of the histogram so that the diagram correctly represents the data even though the first class does not begin at zero.