CH. 12 VOCABULARY
 5.) frequency
 6.) frequency table
 7.) histogram
 8.) cumulative frequency table
12-2 FREQUENCY AND HISTOGRAMS
ALGEBRA 1
DEFINITIONS
 The frequency of an interval is the number of data values in
that interval. A frequency table groups a set of data value into
intervals and shows the frequency for each interval. Intervals in
frequency tables do NOT overlap, do NOT have any gaps, and
are usually of equal size.
 How do you chooser intervals? Look at range first, then divide into 4
or 5 intervals.
EX. 1 MAKE A FREQUENCY TABLE
1a)Use the data to make a frequency table.
 top speeds (mi/h) : 108, 90, 96, 150, 120, 115, 135, 126,
165, 155, 130 125, 100
 1b) Make a cumulative frequency table.
HISTOGRAMS OR BAR GRAPHS
 A histogram is a graph that can display data from a frequency table.
DESCRIBING HISTOGRAMS
 Uniform – The bars are roughly the same height
 Symmetric – If a vertical line can divide the histogram
into two parts that are close to mirror images.
 Skewed – If the histogram has one peak that is NOT in
the center.
EX. 2 DRAW A HISTOGRAM
 Use the data to make a histogram.
 2) ages of relatives: 18, 5, 27, 34, 56, 54, 9, 14, 35,
22, 78, 94, 47, 52, 2, 16, 17, 10
EX. 3 TELL WHETHER THE HISTOGRAM IS UNIFORM, SYMMETRIC OR
SKEWED FOR EX. 2
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