well, as I see it Person1 is faster than Person2, but Person2 doesn't factor in the issue here, let's nevermind Person2.
most of the procedures are 45mins each, namely on average they're 45 mins each.
so Person1 say did 9 procedures, but two of those guys took much longer, too 2 hours each, so two procedures alone ate 4 hours.
Now, Person1 besides doing those two really long procedures, has to also finish the other seven, 2 + 7 = 9, so there are 7 more procedures that on average take 45 mins each.
