He is actually #4. Two oldest got into BYU from a lesser school with similar scores years ago. #3 didn't get into BYU from this same rigorous school with similar GPA but only 26 on the ACT. In fact, no one from this school has been accepted in the last 5 years. They praise you when you get a B, because it is weighted. They literally do not give As in a number of classes. I believe his Junior English IB class gave one A, two A- (which one was him) and the rest lower.
Almost every LDS kid in the AP school down the road has gotten into BYU.