Stats
Lesson 2.2 Bar Graphs, Circle Graphs Notes
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Review:
Example 1: The following data represent baseball batting averages for a random sample
of National League players near the end of the baseball season. The data are from the
baseball statistics of The Denver Post.
0.194
0.250
0.309
0.250
0.200
0.258
0.181
0.276
0.246
0.190
0.125
0.287
0.260
0.291
0.107
0.317
0.265
0.185
0.260
0.252
0.182
0.261
0.309
0.215
0.113
a. Multiply each data value by 1000 to “clear” the decimals.
b. Make a frequency table and histogram with your whole-number data. Use five
classes.
c. Divide class limits, class boundaries, and class midpoints by 1000 to get back to
your original data.
Stats
Lesson 2.2 Bar Graphs, Circle Graphs Notes
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Bar Graph:
 Can be vertical or horizontal
 Bars are of uniform width and space
 Lengths of the bars represent the values of the variable being displayed, frequency
or percent of occurrence
 Cluster Bar Graph: bar graph with more than one bar per increment
Pareto chart:
 Bar graph in which the bar height represents frequency of an event and the bars
are arranged from left to right according to decreasing height.
Circle Graph or Pie Chart:
 Wedges of a circle visually display proportional parts of the total population that
share a common characteristic
Time-series Graph:
 Data are plotted in order of occurrence at regular intervals over a period of time.
 Shows chronological order
All graphs must have the following:
1. Title
2. Axes labeled
3. Identify the units of measure
Example 1: Below is the data (in hundreds) showing the enrollment of male students and
female students in a college in the years of 1995, 2000, 2005. Make a cluster bar graph
for this data.
Year 1995 2000 2005
Male
30
34
32
Female 28
35
33
Stats
Lesson 2.2 Bar Graphs, Circle Graphs Notes
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Example 2: Using the data given in Example 1, make a Pareto chart for male students
enrolled for those three years.
Example 3: Using the data in Example 1, make a circle graph to display the distribution
between male and female students in 1995’s enrollment.
Example 4: Using the data given in Example 1, make a time-series graph for the female
student enrollment in those three years.
Stats
Lesson 2.2 Bar Graphs, Circle Graphs Notes
Assignment: p.54 #1, 3, 5, 6b, 12
Label your assignment Lesson 2.2
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