Respuesta :
Answer:
0.947
Step-by-step explanation:
We are told that the true probability of a baby being a girl is 0.479.
This means that probability of a baby being a boy is;
p = 1 - 0.479
p = 0.521
Now,using binomial probability distribution formula we can solve this problem.
P(X=x) = C(n, x) × p^(x) × (1 - p)^(n - x)
We are told that a mound the next four randomly selected births in the country, what is the probability that at least one of them is a boy.
This is;
P(X ≥ 1) = P(1) + P(2) + P(3) + P(4)
P(1) = C(4, 1) × 0.521^(1) × (1 - 0.521)^(4 - 1)
P(1) = 0.229
P(2) = C(4, 2) × 0.521^(2) × (1 - 0.521)^(4 - 2)
P(2) = 0.3737
P(3) = C(4, 3) × 0.521^(3) × (1 - 0.521)^(4 - 3)
P(3) = 0.27096
P(4) = C(4, 4) × 0.521^(4) × (1 - 0.521)^(4 - 4)
P(4) = 0.0737
Thus;
P(X ≥ 1) = 0.229 + 0.3737 + 0.27096 + 0.0737
P(X ≥ 1) = 0.94736
P(X ≥ 1) ≈ 0.947
