What are the chances of having a girl after having 3 boys?

(assuming that the probability of having a girl or a boy is 50/50)

Looking from beforehand, the probability of having three boys then a girl is the probability of each of these events happening multiplied together. That is 50% x 50% x 50% x 50% or 0.54 This would mean that the chance of having a girl after three boys is 0.0625.

If you've already had the three boys though, it is a different story. The point is that previous experiences do not affect future ones; probability has no memory. Thus the probability of having a girl next is 50%, regardless of if you've had boys or girls in the past. To think otherwise is known as the gambler's fallacy, where a gambler says "black has come up 4 times in a row, it must be red next" even though the chance of red is always 50%