SOLUTION: a die is rolled twenty times.What is the probability of getting exactly four two's?

Question 574586: a die is rolled twenty times.What is the probability of getting exactly four two's?
Answer by jim_thompson5910(35256) (Show Source): You can put this solution on YOUR website!
Use the binomial probability formula

P(X = x) = (n C x)*(p)^(x)*(1-p)^(n-x)

P(X = 4) = (20 C 4)*(0.1667)^(4)*(1-0.1667)^(20-4)

P(X = 4) = (20 C 4)*(0.1667)^(4)*(0.8333)^(20-4)

P(X = 4) = (4845)*(0.1667)^(4)*(0.8333)^16

P(X = 4) = (4845)*(0.000772)*(0.054053)

P(X = 4) = 0.202177

So the probability of getting exactly four two's is 0.202
RELATED QUESTIONS
Suppose a die is rolled 6 times. What is the probability of obtaining: Exactly four (answered by dabanfield)

Find the probability of getting exactly three 5s if a die is rolled 5... (answered by edjones)

A die is tossed 12 times. What is the probability of getting exactly three... (answered by stanbon,jim_thompson5910)

A fair die is to be rolled 12 times. What is the probability of getting at most two... (answered by stanbon,ewatrrr)

A fair die is rolled six times. Calculate the probability of obtaining exactly two... (answered by stanbon)

A fair die is rolled five times. What is the probability of obtaining exactly one... (answered by ewatrrr)

A die is rolled 15 times. What is the probability of at least two 2's appearing? (Round... (answered by stanbon)

If a fair die is rolled 7 times, what is the probability, to the nearest thousandth, of... (answered by greenestamps,ikleyn)

If a fair die is rolled 4 times, what is the probability, to the nearest thousandth, of... (answered by greenestamps)