ECON 2B03 Lecture Notes - Frequency Distribution, Observational Error, Cumulative Frequency Analysis
13 Oct 2013
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Document Summary
Quantitative (discrete or continuous: regardless of the data type, data should be: Collectively exhaustive: (must exhaust all logical possibilities for classifying available data) Mutually exclusive: (must not overlap or have data in common) One immediately confronts the issue of how many classes to create. Desirable number of classes=k, where k is the integer closest to (use standard rules for rounding) 1+ 3. 3 log 10 n, where n is the sample size, and where log 10 n is the power to which the base (10) is raised to yield n. Ex: if n=1,000 than log 10 1000=3, so 1+3. 3 log 10 1000=10. 9 and therefore k=11 so by sturgess"s rule you would use 11 classes when n=1,000. : if you don"t know how many classes to use; use this rule. Class width: the difference between the lower and the upper limits of a class. To achieve uniform class widths in a table, divide the data set width by desirable class number.
