If you were the top 3.8% of your class, would UT, when applying to your specific major see it as a 4.0% or purely just as a 3.8%? In essence, do they round your class rank percentile when determining admission to your specific major(NOT auto-admit), or do they see and use your class rank specifically as it is(no rounding).
No they do not round. Go look at the Academic Index formula. UT actually uses your class rank minus 100% so at 3.8% your class rank factor would be 0.962.