The histogram calculates several kinds of histograms for one or more variables. The types of histogram created are determined by the options selected.
The "Input Range" entry contains a single range or a list of ranges, that can be grouped into variables by rows, columns, or areas. The "Bin Range" entry contains a single range of cutoff values. Both ranges may also include labels.
If the first row or column of the given input ranges, or the first field of each area contains labels, the "Input Labels" option should be selected.
If the first column of the given bin range contains labels, the "Bin Labels" option should be selected.
The remaining options modify the appearance of the histogram:
The "Pareto" option causes the bins to be sorted by decreasing frequency of the first variable.
The "Percentage" option adds a histogram in terms of percentages rather than frequencies.
The "Cumulative Percentages" option adds a cumulative histogram.
The "Chart" option is not implemented.
Example 14-8. Using the Histogram Tool
For example, you want to calculate a histogram and a cumulative histogram in percentages for a the number of successes in several sequences of trials. The numbers of successes are recorded in column A and the classes of interest in column D with labels in column C (see Figure 14-27).
Enter A1:A21 in the "Input Range:" entry by typing this directly into the entry or clicking in the entry field and then selecting that range on the sheet. In the latter case the entry will also contain the sheet name.
Since you only have one variable select the "Areas" or "Columns" radio button next to "Grouped By:".
Enter C1:D5 in the "Bin Range:" entry.
Select the "Bin Labels" option since the first column of the Bin Range contains labels.
Select the "Percentage" and "Cumulative Percentages " options.
Specify the output options as described above.
Press the OK button.
The results are shown in Figure 14-28.