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Sierra College – Math 13
Spring 2009 – Class 5/32
Today: Sections 2-4; 3-1/3-2
Assignment: 2-4 {1, 5, 7, 9, 11, 13, 15}
3-2 {1, 3, 5, 7, 9, 11, 13, 15, 17}
Next: Sections 3-3/3-4
Instructor: John Burke
E-mail: [email protected]
Web Page: http://math.sierracollege.edu/Staff/JohnBur ke/
Telephone: 916 337-0425
Office hours: (V-307) MW 2:35-5:00; M 2:45-3:45 (official)
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2-4 Statistical Graphics
The main objective in using graphic al representations
of data is to better understand the data through:
– Description (center, shape, etc.),
– Exploring (relative strengths), and
– Comparing (data from different populations)
3
Frequency Polygon
A frequency polygon uses line segments connected
to points located directly above class midpoint
values. The heights of the points corr espond to the
class frequencies, and the line se gments are
extended to the right and left so that the graph begins
and ends on the horizontal axis.
13
10
7
4
1
112 – 14
29 – 11
156 – 8
143 – 5
200 – 2
Frequency
Rating
Class midpoints
