USA Today: 75% of ACT test-takers will require remedial help
According to the article:
ACT scores continue to show huge gaps remain between the preparation students receive in high school and what they need to succeed in college. Only 22% met a benchmark score for college readiness in all four subjects — English, math, reading and science. That's a one-percentage-point decline from last year.
On three of the subject tests, the proportions earning scores that indicate college readiness were identical to a year ago — math (43 percent), reading (53 percent) and science (28 percent). The proportion showing college readiness in English fell one point to 68%.
Note that these numbers should actually be lower for the entire student population: in states where all students are required to take the ACT, it takes place in the junior or senior year of high school after many of the dropouts have already left. Factoring those students in would result in lower numbers here.