1. Can more than one set of data be displayed on a box and whisker plot?
Yes, the box and whisker diagram is excellent for displaying, side by side, more than one set of data.
This allows for easy comparison of features such as the median, quartiles, and maximum and minimum values.
2. Can the median, quartiles and percentiles be found on a stem and leaf graph?
Yes. You have to work out the position of the median in the list of values.
e.g. If there are 21 values, the median is the 11th value. You then count in to the 11th value from the highest end or the lowest end of the diagram. Use a similar method for the quartiles and percentiles.