Bar Graphs and Bar Graphs and HistogramsHistograms
PRINCESS C. BARCEGA
APG SCHOOL, MANAMA, BAHRAIN
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What do you know aboutWhat do you know about
bar graph?bar graph? double bar graph?double bar graph? Histogram?Histogram?
Bar GraphBar Graph
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English
Hindi
Mandarin
Spanish
A bar graph can A bar graph can be used to be used to display and display and compare datacompare data
The scale The scale should include should include all the data all the data values and be values and be easily divided easily divided into equal into equal intervals.intervals.
How to interpret a Bar GraphHow to interpret a Bar Graph??
How many of Mr. How many of Mr. Snowden’s Snowden’s students are students are band members?band members?
How many of Mr. How many of Mr. Snowden’s Snowden’s students are not students are not band members?band members? 0
12
34
56
7
Femaleband
Female notband
Male band Male notband
The bar graph shows Mr. Snowden’s The bar graph shows Mr. Snowden’s students by gender and band students by gender and band
membershipmembership..
Double Bar GraphDouble Bar Graph
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1stQtr
2ndQtr
3rdQtr
4thQtr
Can be used to Can be used to compare two compare two related sets of related sets of datadata
How to make a Double-Bar How to make a Double-Bar GraphGraph??
Choose a scale and interval Choose a scale and interval for the vertical axis.for the vertical axis.
Draw a pair of bars for each Draw a pair of bars for each country’s data. Use different country’s data. Use different colors to show males and colors to show males and females.females.
Label the axes and give the Label the axes and give the graph a titlegraph a title..
Make a key to show what Make a key to show what each bar represents.each bar represents.
The table shows the highway The table shows the highway speed limits on interstate speed limits on interstate roads roads . .within three stateswithin three states
StateStateUrbanUrbanRuralRural
FloridaFlorida65mi/h65mi/h70 mi/h70 mi/h
TexasTexas70 mi/h70 mi/h70 mi/h70 mi/h
VermontVermont55mi/h55mi/h65 mi/h65 mi/h
Step 1Step 1
Choose a scale Choose a scale and interval for the and interval for the vertical axis.vertical axis.
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StateStateUrbanUrbanRuralRural
FloridaFlorida65mi/h65mi/h70 mi/h70 mi/h
TexasTexas70 mi/h70 mi/h70 mi/h70 mi/h
VermontVermont55mi/h55mi/h65 mi/h65 mi/h
Step 2Step 2 Draw a pair of bars for each Draw a pair of bars for each
state’s data. Use different state’s data. Use different colors to show urban and rural.colors to show urban and rural.
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80
Florida Texas Vermont
StateStateUrbanUrbanRuralRuralFloridaFlorida65mi/h65mi/h70 mi/h70 mi/h
TexasTexas70 mi/h70 mi/h70 mi/h70 mi/h
VermontVermont55mi/h55mi/h65 mi/h65 mi/h
Step 3 and 4Step 3 and 4
Label the axes and Label the axes and give the graph a give the graph a title.title.
Make a key to Make a key to show what each show what each bar representsbar represents
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Florida Texas Vermont
Spe
ed L
imit
(mi/h
)
Urban
Rural
Speed Limit on Interstate Roads
HistogramHistogram
Histogram is a bar graph that Histogram is a bar graph that shows the frequency of data shows the frequency of data within equal intervals.within equal intervals.
There is no space in between There is no space in between the bars. the bars.
How to make a histogramHow to make a histogram??
The table below shows the number of The table below shows the number of hours students watch TV in one week hours students watch TV in one week
Make a histogram of all the dataMake a histogram of all the data..
Number of hours of TVNumber of hours of TV
11IIII66IIIIII
22IIIIIIII77IIII - IIIIIIII - IIII
33IIII - IIIIIIII - IIII88IIIIII
44 IIII - IIIII - I99IIIIIIII
55 IIII - IIIIIII - III
Step 1Step 1 Make a frequency Make a frequency
table of the data. table of the data. Be sure to use Be sure to use equal intervalsequal intervals
Number of hours of TVNumber of hours of TV
11IIII66IIIIII
22IIIIIIII77IIII - IIIIIIII - IIII
33IIII - IIIIIIII - IIII88IIIIII
44 IIII - IIIII - I99IIIIIIII
55 IIII - IIIIIII - III
Number of Number of hours of TVhours of TV
FrequencyFrequency
1-31-31515
4-64-61717
7-97-91616
Step 2Step 2
Number of Number of hours of TVhours of TV
FrequencyFrequency
1-31-31515
4-64-61717
7-97-91616
Choose an appropriate scale and interval for the vertical Choose an appropriate scale and interval for the vertical axis. The greatest value on the scale should be at least as axis. The greatest value on the scale should be at least as great as the greatest frequency.great as the greatest frequency.
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Step 3Step 3 Draw a bar for each interval. Draw a bar for each interval.
The height of the bar is the The height of the bar is the frequency for that interval. frequency for that interval. Bars must touch but not Bars must touch but not overlap.overlap.
Label the axes and give the Label the axes and give the graph titlegraph title
Hours of Television Watched
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1-3 4-6 7-9Hours
Nu
mb
er
of
stu
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nts
Number of Number of hours of TVhours of TV
FrequencyFrequency
1-31-31515
4-64-61717
7-97-91616
Hours of Television Watched
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4
8
12
16
20
1-3 4-6 7-9
Hours
Nu
mb
er
of
stu
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nts
Can you now make a bar Can you now make a bar graph, double bar Graph graph, double bar Graph
and a histogramand a histogram??
The list below shows the results of The list below shows the results of a typing test in words per a typing test in words per minute. Make a histogram of the minute. Make a histogram of the data.data.
62, 55, 68, 47, 50, 41, 62, 39, 54, 62, 55, 68, 47, 50, 41, 62, 39, 54, 70, 56, 70, 56, 47, 71, 55, 60, 4270, 56, 70, 56, 47, 71, 55, 60, 42
The endThe end