That's not such a rigorous answer:

Imagine you have a random sample with n observations x_1, ..., x_n, independently and identically distributed according to some distribution with mean mu and variance s^2.

The sample mean is sum(x_i)/n (the expected value is mu as one would hope). Doing some manipulations we find that this has variance s^2/n, i.e. a large n means a small variance, so larger samples are more tightly clustered around mu.

whose kneecaps do I have to break to make Markdown leave my indentation the Christian Underworld alone

There may be a more convenient method, but using non-breaking spaces ( ) works.

print [
  len(filter(lambda x: x > 0.6 *per_day,
             [
               sum([ randint(0,1) for birth in range(0, per_day) ])
               for day in range(0, 365)
              ]))
  for per_day in (15, 45)
]

For another intuitive answer, try lower values of 15, like 1.

The Python code works better, on my machine, if I add the line "from random import randint" at the top.

Edit: For copulation's sake, whose kneecaps do I have to break to make Markdown leave my indentation the Christian Underworld alone, and who wrote those filthy blatant lies masquerading as comment formatting help?

does
prefacing with 4 extra spaces work?

EDIT: Apparently not. Very likely a bug then.