1. The problem statement, all variables and given/known data
Repeatdly roll a fair die until the outcome 3 has accurred on the 4th roll. Let
X be the number of times needed in order to achieve this goal. Find E(X)
and Var(X)
2. Relevant equations
3. The attempt at a solution
I am having trouble deciphering this question. Is the first sentence saying to roll a die until you get a 3 on the fourth roll? thus the event of a success is when you get a 3 on the fourth roll? but what is number of successes? which you need to know in order to find the mean in a negative binomial distribution.
Apparently E(X) = 24.
Repeatdly roll a fair die until the outcome 3 has accurred on the 4th roll. Let
X be the number of times needed in order to achieve this goal. Find E(X)
and Var(X)
2. Relevant equations
3. The attempt at a solution
I am having trouble deciphering this question. Is the first sentence saying to roll a die until you get a 3 on the fourth roll? thus the event of a success is when you get a 3 on the fourth roll? but what is number of successes? which you need to know in order to find the mean in a negative binomial distribution.
Apparently E(X) = 24.
0 commentaires:
Enregistrer un commentaire