MATH 321 Lecture Notes - Lecture 20: Cumulative Frequency Analysis, Ogive, Frequency Distribution
6 Jul 2019
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Document Summary
A third type of graph that we can be asked to make from our frequency distribution table is called an ogive. An ogive looks at plotting dots again, but for the plotting dots, we want to go upper class boundary, cumulative frequency so that we can see how the data values have accumulated over those spans. So what we need to do to make this is get another column within our frequency distribution table which is the cumulative frequency. You can think of this as the running total of all the frequencies of classes we have. To get to the cumulative, you would do 7 for the first, then 7+3, then that number, 10, + 2 and so on. Now with an ogive, the data points we plot are the (upperclass boundary, cumulative frequency) On the vertical axis (y axis) write cumulative frequency. On the marking on the x axis, don"t mark midpoint, mark class boundaries.
