Married couples - geometric distribution

irony of truth
Messages
89
Reaction score
0
A couple plans to continue having children until they have their first girl. Suppose the probability that a child is a girl is 0.5, the outcome of each birth is an independent event, and the birth at which the first girl appears has a geometric distribution. What is the couple's expected family size? Is the geometric pdf a reasonable model?

The expected value of a geometric dist. is 1/p = 1/0.5 = 2.

My problem is the 2nd question: from my point of view.. my answer is yes. Bec. the even only concerns w/ success-girl and failure-boy. Is my reason enough to say that gd. is the reasonable model? =)
 
Physics news on Phys.org
The probability that they will have n children (n >=1) is .5n. I presume that is a case of geometric distribution.
 

Thread 'Roulette wheel physics and probability'

Hi all, I've been a roulette player for more than 10 years (although I took time off here and there) and it's only now that I'm trying to understand the physics of the game. Basically my strategy in roulette is to divide the wheel roughly into two halves (let's call them A and B). My theory is that in roulette there will invariably be variance. In other words, if A comes up 5 times in a row, B will be due to come up soon. However I have been proven wrong many times, and I have seen some...
View full post »
Thread 'Detail of Diagonalization Lemma'

Thread 'Detail of Diagonalization Lemma'

The following is more or less taken from page 6 of C. Smorynski's "Self-Reference and Modal Logic". (Springer, 1985) (I couldn't get raised brackets to indicate codification (Gödel numbering), so I use a box. The overline is assigning a name. The detail I would like clarification on is in the second step in the last line, where we have an m-overlined, and we substitute the expression for m. Are we saying that the name of a coded term is the same as the coded term? Thanks in advance.
View full post »

Similar threads

Random Variables - Distribution and Expectations
Replies
1
Views
3K
MHB Probability distribution of girls
Replies
2
Views
5K
Understanding the meaning of "expected fraction" (Statistics)
Replies
4
Views
2K
What Is the Probability That Exactly 3 Out of 8 Children Are Girls?
Replies
2
Views
2K
Geometric distribution problem
Replies
2
Views
12K
Seeking psychological help: Tricks to deal with being really envious?
Replies
1
Views
2K
Conditional expectation and partitioning
Replies
19
Views
2K
Solving the Boy Girl Paradox Probability for Random Families
Replies
9
Views
3K
Probability, Correlation, Variance Statistics Homework Help.
Replies
27
Views
4K
I Is there new LHC data on coupling constant running?
Replies
1
Views
3K

Hot Threads

Recent Insights

Back
Top