Stem & leaf, Bar graphs, and Histograms
- 1. Stem and Leaf Plot Consists of Numbers on the left, called the stem (does not include the ones place) Numbers on the right, called the leaf (ones place) Works well when the data contains more than 25 elements; the data is collected in a frequency table; the data values span many “tens” of values.
- 2. Stem and Leaf Plot 1, 5 , 5 , 8 , 8 , 8 , 10 , 12 , 12 , 13 , 14 , 2 0 , 2 3 , 5 9 , 8 2 , 112 stem leaf
- 3. Advantages of Stem and Leaf Plots It can be used to quickly organize a large list of data values. It is convenient to use in determining median or mode of a data set quickly. Outliers, data clusters, or gaps are easily visible. Disadvantages of Stem and Leaf Plots A stem and leaf plot is not very informative for a small set of data.
- 4. Bar Graph Consists of bars of the same width drawn either horizontally or vertically; bars whose length (or height) represents the frequencies of each value in a data set. Works well when the data is numerical or categorical; the data is discrete; the data is collected using a frequency table.
- 6. Advantages of Bar Graphs The mode is easily visible. A bar graph can be used with numerical or categorical data. Disadvantages of Bar Graphs A bar graph shows only the frequencies of the elements of a data set.
- 7. Histogram Consists of e q u a l i n t e r v a l s marked on the horizontal axis; bars of equal width drawn for each interval (There is n o s p a c e between the bars.) Works well when the data has a really big range there is one set of data the data is collected using a frequency table.
- 8. Histogram Example 70-74 75-79 80-84 85-89 90-94 95-99
- 9. Advantages of Histograms A histogram provides a way to display the frequency of occurrences of data along an interval. Disadvantages of Histograms The use of intervals prevents the calculation of an exact measure of central tendency.