We use cookies to ensure you have the best browsing experience on our website. Please read our cookie policy for more information about how we use cookies.
  1. Prepare
  2. Tutorials
  3. 10 Days of Statistics
  4. Day 3: Conditional Probability
  5. Discussions

Day 3: Conditional Probability

Sort by

recency

|

186 Discussions

|

  • albamorq
     + 0 comments

    the question should change to really address conditional probability. The sex of one child is not affecting the sex of the other, so, in whatever scenario, conditional probability doesn´t appear.

    One scenario that I would like to talk about (even if it is still not related to conditional probability) is if the probability would change if the question would be about the sex of the SECOND child, being that the sex of the first child is boy. In this case, the sample would only contain two states, thus the probability asked would be 1/2, instead of 1/3, right? The thing is that this really resontes with me about prior knowledge (the context in which bayes theorem makes sense) so, i am confused

  • 15inchpython
     + 0 comments

    This isn't a well thought out question. Firstly, guessing the sex of one child is always 1/2. Secondly, ordering doesn't matter. Even if you map it out as {BB, GG, BG, GB}, GG isn't possible and {GB,BG} are the same so you still end up with 1/2.

  • n4m774r_d
     + 0 comments
    import math
from fractions import Fraction

def reducto(num, den):
    pgcd = math.gcd(num, den)
    s_num = num // pgcd
    s_den = den // pgcd
    return s_num, s_den

def prob_direct(nbr_possibilities, favorable_events):
    max_events = nbr_possibilities * nbr_possibilities
    return Fraction(*reducto(favorable_events, max_events))

def prob_comp(frac):
    return 1 - frac

def Bayne(a,b):
     return a/b

A = prob_direct(2, 1)
B = prob_comp(A) 
C = Bayne(A,B)

print("Bayne:",C)

  • ash_rabbi
     + 0 comments

    I think I figured it out via naive reasoning. We know that they have two kids, so, marking a boy as 1 and a girl as 0, there are four options as to what they can be: 00, 01, 10 and 11. Now, we know that one is a boy, so it can't be 00. Thus, there are three options, of which only one, option 11, is what we are looking for. Thus the probability is 1/3.

  • davidsunglee2005
     + 1 comment

    Sex probability is an INDEPENDENT event. Thus every time the sex is 50/50.

    This is a bad example of conditional probability. How does the sex of the first child affect the probability of the sex of the second child? These are independent events.