Unit 2 – Univariate Data: Organizing Data

Key Definitions:

1)Box and Whisker or 5 Number Summary

2)Stem and Leaf Plot: Two column table

  1. Stem represents a factor of 10
  2. Leaf represents one less factor of 10 and frequency
  3. Can be used for a small range and a low number of data values
  4. Visual for helping to identify measures of central tendency

3)Frequency Distribution: Table that shows how often a data value or group of data values appears , example using tally marks, for a given class or interval

4)Class or Interval: group of data values

  1. Class width or interval: range of values for each class
  2. Lower Class Limit: least value of the class
  3. Upper Class Limit: greatest value of the class
  4. Class Mark: average of the class limits

5)Frequency

  1. Frequency:tallies the number in each class
  2. Relative Frequency: ratio of the data within a class to all of the data
  3. Cumulative Frequency: for a class that includes its frequency sum and all previous frequencies. Note the last class should reflect the total number of data values.
  4. Cumulative Relative Frequency: ratio of the cumulative frequency to all of the data, the sum of all of the Cumulative Relative Frequencies should equal “1”.

6)Histogram: frequency data can also be expressed as a bar graph where

  1. Intervals are used for possible horizontal values
  2. Frequency is used for possible vertical values
  3. Intervals/bars on the graph are side-by-side
  4. Cumulative relative frequency histogram goes from 0 to 1

Range: the difference between the greatest and least values in a set of data

Example 4 in Glencoe Precalculus Textbook, P37, #12 to discuss Cumulative Relative Frequency

AMC Workbook – 14.2 Practice Measures of Central Tendency with Stem and Leaf Plot and simple frequency table to expand with relative frequency

AMC Workbook – 14.1 Frequency Distributionswith histogram example and practice to determine class intervals and create frequency distribution table and histogram.