ACT was not considered in SLO admissions this year. Also they use 9-11th grades in their GPA calculation and it can also depend upon your applied major. Biological sciences had a projected acceptance rate around 10% so the majority of applicants would be denied. Look at the SLO Stats thread and see for yourself.
Last year, SLO denied 12,000 applicants that had over 4.0 GPA’s. Just too many high achieving students for the few spots that are available, the definition of impaction.