Yahoo Answers: Answers and Comments for Roll a die 10 times. find chance of exactly 4 twos? [Mathematics]
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From Lynette
enUS
Thu, 12 Dec 2019 08:28:35 +0000
3
Yahoo Answers: Answers and Comments for Roll a die 10 times. find chance of exactly 4 twos? [Mathematics]
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From Alan: Use the binomial probability formula .
P( ex...
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https://answers.yahoo.com/question/index?qid=20191212082835AAiak6G
Thu, 12 Dec 2019 08:52:05 +0000
Use the binomial probability formula .
P( exactly k events in n trials) = (n k) p^(k) (1p)^(nk)
where (n k ) = nCk = n! / ( (nk)! k!)
n = number of trials
k = exact number of successes
p = probability of success in one trial
so
P(exactly 4 twos in 10 trials) = ( 10 4) (1/6)^4 (5/6)^6
P(exactly 4) = (10 4) (5^6/6^10)
(10 4) = 10! / (6! *4!) = 10*9*8*7 / 4*3*2*1
(10 4) = 10*9*7/3 = 10*3*7 = 210
p(exactly 4) = 210 * 5^6/6^10
P(exactly 4 ) = 3281250 /60466176
P(exactly 4 ) = 546875 / 10077696
P(exactly 4 ) = approx. 0.054265876
so about a 5.43 % chance so not very probable

From Pope: The number of 2s has a binomial distribution.
...
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Thu, 12 Dec 2019 08:41:37 +0000
The number of 2s has a binomial distribution.
p = probability of success on any single trial = 1/6
n = number of trials = 10
r = number of successes = 4
required probability = C(n, r) p^r (1  p)^(n  r)

From Jimmy: 50/50
either it happens or it doesn't happen
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https://answers.yahoo.com/question/index?qid=20191212082835AAiak6G
Thu, 12 Dec 2019 08:31:34 +0000
50/50
either it happens or it doesn't happen