HELP

[tltdas]

I have a question. Here it is!!!!!!!!

What is the probability that 13 rolls of a fair die will show three fours?I am not quite sure what formula I must use in order to figure this out! Any help would be appreciated.

Thank you so much!
Tara

 

[pka]

See this response: http://www.mathgoodies.com/forums/topic.asp?TOPIC_ID=24337

n=13, x=3 & p=[1/6].

 

[Denis]

Is this an "ok" way to look at this, pka:

after 6: 1
after another 6: 1 again
now one left, so 1/6

 

[tkhunny]

If you define a Poisson distribution, it's not TOO bad.

[lambda] = 13/6 = Expected number of any specific value.

Pr(3 of anything) = 0.194, a little less than the true Binomial for 3.