Exceeding three standard deviations is expected to happen only in 0.15% of the cases, so the state has clearly set an extremely conservative rule in order to avoid unfairly tainting any school's reputation. The odds of hitting this rule without there being cheating in at least some of that 25% of classrooms is literally infinitesimal (so small as to be unmeasurable).
And even more astounding, there are schools on the list where 80%+ of classrooms exceeded this amount. ALL FOUR of these were within the Atlanta Public Schools system.
* Frank L Stanton Elementary, 83.3%
* Peyton Forest Elementary, 86.1%
* Gideons Elementary, 88.4%
* Parks Middle, 89.5%
With school rates this insanely high it strains credibility that these were individual teachers acting alone, and with 58% of all elementary schools in Atlanta Public Schools implicated it strains credibility that these were individual principals acting alone. Numbers like this can only point to the top of the system's administration. Either the superintendent Beverly Hall was in on it or she is a blithering idiot of monumental proportions. Either way, she has to go. Now!