This document defines and provides examples of three different types of plots used to represent data distributions: stem and leaf plots, bar graphs, and histograms. It explains that stem and leaf plots organize large data sets by separating values into "stems" and "leaves", bar graphs represent frequencies using bars of equal or varying widths, and histograms use intervals to group continuous data and display frequencies. The document also lists advantages and disadvantages of each type of plot.

1. Stem and Leaf Plot
Consists of
 Numbers on the left, called the stem
(does not include the ones place)
 Numbers on the right, called the leaf
(ones place)
Works well when
 the data contains more than 25 elements;
 the data is collected in a frequency table;
 the data values span many “tens” of
values.

2. Stem and Leaf Plot
1, 5 , 5 , 8 , 8 , 8 , 10 , 12 , 12 , 13 , 14 ,
2 0 , 2 3 , 5 9 , 8 2 , 112
stem leaf

3. Advantages of
Stem and Leaf Plots
 It can be used to quickly organize a large list of
data values.
 It is convenient to use in determining median or
mode of a data set quickly.
 Outliers, data clusters, or gaps are easily
visible.
Disadvantages of
Stem and Leaf Plots
 A stem and leaf plot is not very informative for a small
set of data.

4. Bar Graph
Consists of
 bars of the same width drawn either horizontally
or vertically;
 bars whose length (or height) represents the
frequencies of each value in a data set.
Works well when
 the data is numerical or categorical;
 the data is discrete;
 the data is collected using a frequency table.

5. Bar Graph Example

6. Advantages of Bar Graphs
 The mode is easily visible.
 A bar graph can be used with numerical or
categorical data.
Disadvantages of Bar Graphs
 A bar graph shows only the frequencies of the
elements of a data set.

7. Histogram
Consists of
 e q u a l i n t e r v a l s marked on the
horizontal axis;
 bars of equal width drawn for each interval
(There is n o s p a c e between the bars.)
Works well when
 the data has a really big range
 there is one set of data
 the data is collected using a frequency table.

8. Histogram Example
70-74 75-79 80-84 85-89 90-94 95-99

9. Advantages of Histograms
 A histogram provides a way to display the
frequency of occurrences of data along an
interval.
Disadvantages of Histograms
 The use of intervals prevents the calculation of
an exact measure of central tendency.