M ARIO F. T RIOLA E IGHTH E DITION E LEMENTARY S TATISTICS Section 2-3 Pictures of Data.
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Transcript of M ARIO F. T RIOLA E IGHTH E DITION E LEMENTARY S TATISTICS Section 2-3 Pictures of Data.
MARIO F. TRIOLAMARIO F. TRIOLA EIGHTHEIGHTH
EDITIONEDITION
ELEMENTARY STATISTICSSection 2-3 Pictures of Data
Pictures of DataPictures of Data depict the nature or shape of the data
distribution
Histograma bar graph in which the horizontal
scale represents classes and the vertical scale represents frequencies
Figure 2-2
Histogram of Qwerty Word Ratings
0 - 2 20
3 - 5 14
6 - 8 15
9 - 11 2
12 - 14 1
Rating Frequency
Relative Frequency Histogram of Qwerty Word Ratings
Figure 2-3
0 - 2 38.5%
3 - 5 26.9%
6 - 8 28.8%
9 - 11 3.8%
12 - 14 1.9%
RatingRelative
Frequency
Histogram and
Relative Frequency Histogram
Figure 2-2 Figure 2-3
Frequency Frequency PolygonsPolygons
A frequency polygon is created by joining class midpoints of each class of a histogram by line segments.
To complete the polygon, assume a class interval with zero frequency before the first class interval. Connect that point with the next class’s midpoint, and then connect all class midpoints. Assume a class interval with zero frequency after the last class interval.
Frequency Frequency PolygonsPolygons
Ogive (called “o-Ogive (called “o-jive”)jive”)
An ogive is a graph that represents the cumulative frequencies for the classes in a frequency distribution. It shows how many of values of the data are below a certain boundary.
Figure 2-5
Ogive
Dot Dot PlotPlot
A dot chart or dot plot is a chart that is made up of a group of data points plotted on a simple scale. These plots are suitable for small to moderate sized data sets, and can highlight gaps and outliers.
GapsGaps
Figure 2-6
Dot PlotDot Plot
Stem and Leaf Stem and Leaf PlotsPlots
Stem-and-leaf plots are a method for showing the frequency with which certain values occur. To construct a stem plot:
Sort data points in ascending orderThe leaf will contain the last digit of
the number, and the stem will contain all
otherdigits.
Stem and Leaf PlotsStem and Leaf Plots
Stem-and Leaf PlotStem-and Leaf Plot
Raw Data (Test Grades)
67 72 85 75 89
89 88 90 99 100
Stem Leaves
6 7 8 910
72 55 8 9 90 9 0
Pareto ChartPareto ChartA Pareto chart is a bar graph that
helps identify which parts of a data set occur most frequently, and it puts those parts first.
It shows, in descending order and from left to right, the frequency of events being studied.
Pareto Chart
Figure 2-7
5,000
10,000
15,000
20,000
25,000
30,000
35,000
40,000
45,000
0
Mo
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Ve
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Fa
lls
Po
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Dro
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ing
Fir
e
Ing
es
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f fo
od
or
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Fir
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Frequency
Accidental Deaths by Type
Pie Chart
Figure 2-8
Firearms(1400. 1.9%)
Ingestion of food or object(2900. 3.9%
Fire(4200. 5.6%)
Drowning(4600. 6.1%)
Poison(6400. 8.5%)
Falls(12,200. 16.2%)
Motor vehicle(43,500. 57.8%)
Accidental Deaths by Type
Scatter Diagram
••
••
••
••
• •••
••
0
0.0 0.5
••
•••
•
1.0 1.5
10
20
•
NICOTINE
TA
R
Figure 2-9
Deaths in British Military Hospitals During the Crimean War
Boxplots (textbook section 2-7)
Pictographs
Pattern of data over time
Other Graphs