Answer:
P(X ≥ 3) = 0.94538
Step-by-step explanation:
When flipping a coin, probability of getting a tail is p= 0.5.
Number of times flipped; n = 10
Now, this is a binomial probability distribution problem with the formula;
P(X = x) = C(n, r) × p^(x) × (1 - p)^(n - x)
Probability of getting at least 3 tails is;
P(X ≥ 3) = P(3) + P(4) + P(5) + P(6) + P(7) + P(8) + P(9) + P(10)
P(3) = C(10, 3) × 0.5³ × (1 - 0.5)^(10 - 3)
P(3) = 0.1172
P(4) = C(10, 4) × 0.5⁴ × (1 - 0.5)^(10 - 4)
P(4) = 0.2051
From online binomial probability calculator, we have the remaining as;
P(5) = 0.2461
P(6) = 0.2051
P(7) = 0.1172
P(8) = 0.0439
P(9) = 0.0098
P(10) = 0.00098
Thus;
P(X ≥ 3) = 0.1172 + 0.2051 + 0.2461 + 0.2051 + 0.1172 + 0.0439 + 0.0098 + 0.00098
P(X ≥ 3) = 0.94538
