The Chicago Tribune found 8 of 10 public high school juniors in Illinois scoring below the college readiness measures of the ACT test, reported in this article. "The nonprofit ACT company stands by its readiness scores: at least 18 in English, 21 in reading, 22 in math and 24 in science. The top possible score is 36."
This includes students from high schools of high repute, like New Trier, where 94% go to college. Even there, 38% of juniors fell short of the readiness scores.
"In Lincolnshire and Naperville [posh and highly-regarded programs], more than half of juniors scored too low to reach the targets in English, reading, science, and math, though several hundred met three of four benchmarks, usually missing in science."