Yes approximately. By those numbers I mean very high (80-90%) hit probability (assuming centered on target). And this is my experience only with 22lr and groups at distance vs closer range.Do I understand you correctly?
1 MOA @ 50 = 1/2"
1.3 MOA @ 100 ~ 1.3"
1.7 - 1.8 MOA @ 200 ~ 3.4"
2.5 MOA @ 400 ~ 10"
It's not a hard/fast rule; doesn't mean all shots land inside some circle but rather a rough guide to the increasing group size you see as bullets go further down range. I've seen other variations on this also elsewhere.
I think one person (I can't recall whom exactly) called it the Half Third Rule - essentially as distance is cut in half, group size decreases by only 1/3. With rimfire it seems to grow more quickly but I think that's due more to the flight time than anything else.