Hey, this is a good question. I hadn't thought of it that way. Sorry guys, I didn't mean to confuse or mislead anyone. I don't know exactly how many will be accepted from the last interview (and it is impossible to predict) but my estimate of ~45-55 was just my best guest based on the trends i've gathered from this thread. (check out pp. 4-7)
1st interview: 48 or 55 (maybe some accepted had declined)
1st + 2nd combined = ~100 (per Shehsheh)
So, I thought it was reasonable to assume ~45-55 will also get accepted from the last interview batch. The lady at the Adm Office told me that they don't have a specific number they're shooting for, and the # can be lower OR higher than the # accepted from each of the other interviews. The total they're accepting is 250. They'll also review those on active consideration again after the 4th interview.
I don't know if they'll compare ppl in the 4th interview with those on AC before deciding who to admit, or they might take you right away if you're a strong candidate. WITHOUT adding in those on AC and just looking at the 100 that are interviewing on the 29th.... if they accept as low as 30/100, that's still ~1/3 chance to get in. So, a more accurate estimate of our chances is maybe ~1/3-1/2 or even 1/4-1/2. Point is, be encouraged!! I think the odds of making it if you have an interview are better than odds of getting an interview in the first place