Properties of Bar Graphs

1
Properties of Bar Graphs

• Bars can be vertical or horizontal
• Bars are of uniform width and uniformly spaced
• Length of bars represent value of variable being
  displayed
• Graph has title, labels for each bar and scale
  for length of bar

2
Data for Bar Graph

• A recent study on Bronze Age spearheads recovered
  from ancient rivers in Ireland provided the
  following information (see 2.26)

River Bahn Blackwater Erne Shannon Barrow
Number 19 8 15 33 14
3
Bronze Spearheads in Irish Rivers
4
Other Types of Charts

• A Pareto chart is a bar graph in which the bar
  height represents the frequency of an event. In
  addition, the bars are arranged from left to
  right according to decreasing height.
• In a circle graph (or pie chart), wedges of a
  circle display proportional parts of the total
  population that share a common characteristic.

5
Bronze Spearheads in Irish Rivers
6
Time Series Graphs

• In a time series graph, data are plotted in order
  of occurrence in regular intervals over a period
  of time.
• Time series data consists of measurements of the
  same variable for the same subject taken at
  regular intervals over a period of time.

7
Margin of Victory
8
Heights of Boys vs. Age
Age in Years