8.) cumulative frequency table 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. Histograms or Bar graphs

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.

Use the data to make a histogram. 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