T T02-03 Histogram (Equal Classes) Purpose Allows the analyst to analyze quantitative data by summarizing it in sorted format, scattergram by observation, frequency dot plot by data value, equal class width (analyst choice based on beginning, ending and number of classes) frequency histogram and relative frequency histogram. Inputs Original Quantitative DataNumber Classes Beginning ClassEnding Class Outputs Sorted Quantitative DataSummary Statistics Original Data ScattergramFrequency Dot Plot Frequency Histogram Relative Frequency Histogram Limitations 1000 quantitative data
T An Example An accounting firm has collected a sample of audit times from last year. To get a better feel for the distribution of the audit times the manager wants to look at a Histogram of the data using 5 equal width classifications.
T Data can either be entered directly into the Original Data cells or copy/paste special/values into the cells.
T Once the data is entered Summary Statistics ( Count, Max, Min & Range ) are automatically calculated. The Sort Macro can be run to sort the Original Data into the Sorted Data cells. This also automatically calculates the necessary information for the Dot Plot.
T The Summary Statistics (Max & Min) can be used to establish the Begin Class Point and the End Class Point. These are then entered with the Number Classes for the Histogram.
T The Equal Class Width and Histogram Bin Classifications are automatically calculated. The Histogram Macro can be run to automatically calculate the Histogram Information.
T The Histogram Information (frequency & relative frequency) is displayed in tabular format by the classifications. Decimal Point Accuracy can be set for the Relative Frequency
T Worksheet Tabs can be selected to view the Original Data Scattergram, Frequency Dot Plot, Frequency Histogram and Relative Frequency Histogram.
T The Scattergram displays a plot of the observations in the sequence they were entered.
T The Dot Plot displays a frequency plot of the observations.
T The Equal Width Frequency Histogram shows the histogram for the number of equal width classes chosen. The legend should be read bottom-up.
T The Equal Width Relative Frequency Histogram shows the histogram for the number of equal width classes chosen. The legend should be read bottom-up.