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27, 27, 28, 28, 28, 28, 29, 29, 29, 30, 30, 30, 30, 30, 31, 31, 32 Frequency Tables It is often convenient to record data in a frequency table. This is particularly useful when there is a large amount of data. The mean, mode, median and range can be calculated directly from the table. Class Size f Here is some data on class sizes in a school. Data placed in a frequency table

Class Size x f fxfx Original data in list form: 27, 27, 28, 28, 28, 28, 29, 29, 29, 30, 30, 30, 30, 30, 31, 31, 32 Frequency Tables Calculating the mean from the frequency table (2 x x x x x x 32) 17 Mean = = 497/17 = 29.2 Or if entered directly into a calculator.

Original data in list form: 27, 27, 28, 28, 28, 28, 29, 29, 29, 30, 30, 30, 30, 30, 31, 31, 32 Frequency Tables Finding the mode, median and range from the frequency table. Class Size f Mode = 30 (Highest frequency) Median = 29 (The middle data value) [(17 + 1)/2 = 9 th data value.] Range = 32 – 27 = 5