IF THREE PEOPLE ARE IN A GROUP,THE CHANCES THAT ANYY TWO HAVE THE SAME BIRTHDAY IS O.OO82 WHAT IS THE CHANCE THAT NO ONE IN THE GROUP HAS THE SAME BIRTHDAYAS ANY PERSON IN THE GROUP??

Question

IF THREE PEOPLE ARE IN A GROUP,THE CHANCES THAT ANYY TWO HAVE THE SAME BIRTHDAY IS  O.OO82 WHAT IS THE CHANCE THAT NO ONE IN THE GROUP HAS THE SAME BIRTHDAYAS ANY PERSON IN THE GROUP??

anonymous · Answer

i guess 1-.0082

amistre64 · Answer

hard to read the all caps

anonymous · Answer

.9918 is what i get

amistre64 · Answer

3 in a group; .0082 chance the 2 have same birthday

anonymous · Answer

naw thats wrong its either 0.9918

anonymous · Answer

nvm your right

amistre64 · Answer

there are 8 outcomes all together

anonymous · Answer

whew!

anonymous · Answer

thanks

anonymous · Answer

@amistre doesn't matter how many outcomes.  this just says the probability of A is .0083 so the probability of not A is 1-.0083

amistre64 · Answer

or is it 4 outcomes :)

nnn
nyy
yny
yyy

anonymous · Answer

actually it is a bit more complicated i think

amistre64 · Answer

itd help better if I could actually read the question ;)

anonymous · Answer

i mean the answer is given, but the calculation to get it is a bit more

amistre64 · Answer

i was wondering if binomial fit; and such ... but yeah

anonymous · Answer

no

amistre64 · Answer

i was confusing at least 2; as well

anonymous · Answer

but actually easy enough to calculate no two same birthdays.  pick one.  they were born some day.  forgetting about leap years then the probability that the next person is not born on the same day is 
$$\frac{364}{365}$$

anonymous · Answer

and the next not either is 
$$\frac{363}{365}$$ and their product is .9918 to four decimal places

anonymous · Answer

more interestingly continuing in this pattern you only need to get two about  23 for the probability to be less than a half, and at around 30 it is only about 30% meaning that in a group of 30 people there is a 70% chance that two or more share a birthday

amistre64 · Answer

side question:  what is a t-distribution?

anonymous · Answer

side answer.  no idea, sorry

anonymous · Answer

i remember something called "students t" but all i remember is the name

amistre64 · Answer

we are going over how to find zscores and area at teh moment and the later chapters build into chi^2 and t distribution thanx to a central limit thrm

amistre64 · Answer

degrees of freedom, hypot testing and confidence intervals ...