Probability of birthdays on every day

[duzza275]

Please may someone help me with this and if you have an answer please may you show all the steps that you took. This is not a prep question but I was thinking about it and wondering what the answer was but my statistics skills are not good enough for this yet. :)

If I have a randomly selected group of 430 people. What is the probability that there is 1 birthday on ever single day in the year? (Assume that it is a 365 day year)

Thanks

 

[gsal]

Good luck...I guess you are asking for an answer from the purely mathematical point of view assuming a uniform distribution of births throughout the year?

I am wondering because that's not what REALLY happens. Weather and holidays affect love-making; last I heard, new year's is a 'lucky' day and so, we have a lot of September people.

Just look at the animal kingdom; ok, they don't have holidays, but look at how the times when, basically, the entire group gives birth within a matter of days or weeks ruled by migratory patterns, availability of food, weather conditions, etc.

Anyway, just a thought.

 

[duzza275]

Yeh I am looking for an answer with a mathematical point of view that assumes that births are evenly distributed throughout the year.

 

[awkward]

Please may someone help me with this and if you have an answer please may you show all the steps that you took. This is not a prep question but I was thinking about it and wondering what the answer was but my statistics skills are not good enough for this yet. :)

If I have a randomly selected group of 430 people. What is the probability that there is 1 birthday on ever single day in the year? (Assume that it is a 365 day year)

Thanks

This is the "Coupon Collector's Problem". See my reply to this post

https://www.physicsforums.com/showthread.php?t=523620

for a formula for the probability.