Answer:
The probability is 32/81
Explanation:
We know that:
The probability that the team wins is p = 2/3
Then the probability of not winning is q = 1 - p = 1 - 2/3 = 1/3
The team plays 4 matches.
We want to find the probability that the team wins 1 more than half of the number of matches played.
So if there are 4 matches, the half is 2 matches
one more than half is then 3 matches.
Let's assume that the team wins the first 3 matches, and does not win the last match.
match one, the team wins with prob: P₁ = 2/3
match two, the team wins with prob: P₂ = 2/3
match three, the team wins with prob: P₃ = 2/3
match four, the team wins with prob: P₄ = 1/3
The joint probability is the product of all the individual probabilities:
P = (2/3)*(2/3)*(2/3)*(1/3)
Now we must also considerate the permutations, we have the cases:
the team does not win the fourth match
the team does not win the third match
the team does not win the second match
the team does not win the first match
So we have just four permutations, then the total probability is:
probability = 4*P = 4*(2/3)*(2/3)*(2/3)*(1/3) = 4*(8/81) = (32/81)