In a charter school of 400 students, the average score on a standardized test at the beginning of the year was 82%.
By the end of the first few months, 92 students couldn't take it anymore: the 9-hour days of which 8.5 hours were spent staring at computer screens, the required Saturday classes and the constant badgering over being quiet, walking dully in a single file, drill, drill, drill, drill, and drill, all seemingly in an effort to get them to drop out.
The 92 students, who were getting Ds and Fs, had a collective average of 60, which is why they were targeted.
In late October, Jay Matthews of the Washington Post interviews the principal for a Thanksgiving-themed piece in the paper and asked about the gains and improvements that the wonderful charter-school had been able to accomplish.
The principal did not mention that the students had not taken the test again or
that the rise was simply because of the elimination of what he
considered inferior students. Instead, the principal said proudly, "Our program is amazing. We have been able to raise their scores by _________ in just two months. If the City gives over some more public schools to our control, we'll be able to do more of this."
How much did scores rise because of the expulsion/removal of the 92 lower-scoring students?