
| Middle of category | Frequency | Frequency % | Cummulative frequency % |
| 3.50 | 124 | 0.9 | 0.9 |
| 3.60 | 4321 | 32.0 | 33.0 |
| 3.70 | 3067 | 22.7 | 55.7 |
| 3.80 | 1564 | 11.6 | 67.3 |
| 3.91 | 742 | 5.5 | 72.8 |
| 4.01 | 477 | 3.5 | 76.3 |
| 4.11 | 349 | 2.6 | 78.9 |
| 4.21 | 305 | 2.3 | 81.2 |
| 4.31 | 275 | 2.0 | 83.2 |
| 4.42 | 206 | 1.5 | 84.8 |
| 4.52 | 242 | 1.8 | 86.6 |
| 4.62 | 275 | 2.0 | 88.6 |
| 4.72 | 333 | 2.5 | 91.1 |
| 4.82 | 468 | 3.5 | 94.5 |
| 4.93 | 348 | 2.6 | 97.1 |
| 5.03 | 152 | 1.1 | 98.2 |
| 5.13 | 74 | 0.5 | 98.8 |
| 5.23 | 40 | 0.3 | 99.1 |
| 5.33 | 35 | 0.3 | 99.4 |
| 5.44 | 21 | 0.2 | 99.5 |
| 5.54 | 11 | 0.1 | 99.6 |
| 5.64 | 7 | 0.1 | 99.6 |
| 5.74 | 5 | 0.0 | 99.7 |
| 5.84 | 4 | 0.0 | 99.7 |
| 5.95 | 3 | 0.0 | 99.7 |
| 6.05 | 2 | 0.0 | 99.7 |
| 6.15 | 2 | 0.0 | 99.8 |
| 6.25 | 5 | 0.0 | 99.8 |
| 6.35 | 7 | 0.1 | 99.9 |
| 6.46 | 7 | 0.1 | 99.9 |
| 6.56 | 3 | 0.0 | 99.9 |
| 6.66 | 3 | 0.0 | 99.9 |
| 6.76 | 2 | 0.0 | 100.0 |
| 6.86 | 2 | 0.0 | 100.0 |
| 6.97 | 0 | 0.0 | 100.0 |
| 7.07 | 0 | 0.0 | 100.0 |
| 7.17 | 1 | 0.0 | 100.0 |
| 7.27 | 0 | 0.0 | 100.0 |
| 7.37 | 0 | 0.0 | 100.0 |
| 7.48 | 2 | 0.0 | 100.0 |
FYI: Regression on these (log-log) data points gives a line with slope of -2.08 and y-intercept of 14.69. The correlation coefficient is -0.930915963003306.
This program is a version of demo.cgi by Sanford Morton, heavily modified by Michael Grobe to include data input, categorization, and regression. The program uses Perl module Chart::Plot, written by Sanford Morton and downloaded from www.speakeasy.org, to draw plots.