Statistic multiple choice question help !?

Question

Which of the following graphical methods cannot be used on a categorical data set?

(a) A bar chart

(b) A pie chart

(c) A stem-and-leaf display

(d) All of the above can be used on a categorical data set.

Answer 1

(c) A stem-and-leaf display

You will often see pie charts with categorical data, for instance the number of polled voters for various presidential candidates.  You can also see bar chart with categorical data, for instance the comparative number of olympic medals won by various countries along the x-axis.  However, stem-and-leaf displays require categorical data become the presentation is numeric.  There is no axis or key where you can include labels for candidate or country names.  

Hope this helps you!