City libaries have internet access. I suspect the school library does too. I am not saying it is as easy, but it can be done.
The short answer is that this is pretty much inevitable. Here is the more complete answer:
- Intelligent people tend to make more money. The estimated correlations are not particularly high (around 0.3), but the trendline is clear.
- Intelligence is significantly hereditary. In other words, smart parents tend to have smart kids. The correlation on this is estimated at 0.8.
- Given 1 and 2 above, statistics makes it highly likely that a high income school district will have higher AVERAGE test scores than a lower income school district.
Note I am not saying there are no intelligent people in less wealthy school district. Nor am I saying all the students in the richer school district are intelligent. The average can mask a great deal of variation.
Because GPA and test scores reveal different information. Test scores provide a common framework for comparison but say nothing about a student’s grit or other personal skills that can set them up for success. The GPA tells about how a student did in their particular school system, but says nothing about how rigorous the high school actually is.
I contend that standardized tests are actually most useful for school systems that are not well known. Every college knows Lexington High School in Massachusetts, and a student’s courses and GPA will tell them everything they need to know about whether the student is ready for UChicago. In contrast, a 4.0 unweighted GPA from Podunk High School may not reveal much, particularly if coupled with a lack of APs.