Question

Find the probability of at least 2 girls in births. Assume that male and female births are equally likely and that the births are independent events. Round to three decimal places.

Answer 1

We assume that male and female births are equally likely, it means that the probability of birth of male= probability of birth of female = 100%/2=50% or 0.5We have 2 independent events. So what will be the variants:
Male and FemaleMale  and Male Female and Male Female and Female 
All four variants are equally likely.Probability of each one is 1/4 = 0.25.So, Result "Female and Female"
 are probability = 0.250 --- if round to three decimal places.