Clear to you maybe and even possible, but all are estimates and speculations and such are discussed as estimations. And then there are other things we can throw at the Text and never get answered - how did 3,000 hear Peter? - were 100,000 (some say 250k, some say 30k, etc.) there where Peter was at the time? - how many at the snack bars and Jerusalem porta-johns and missed the best scene? - etc...
Speculate all you want and as wildly as you want or don't want. Join the crowd who do various estimations using various factors and call each other stupid for their estimations. The Text says what it says, and your argument is from silence.