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.