answer:
To compute the probability of x successes in n independent trials of a binomial probability experiment, we use the binomial probability formula:
P(x) = (n C x) * p^x * (1-p)^(n-x)
In this case, we have the following parameters:
- Probability of success, p = 0.6
- Number of independent trials, n = 9
- We want to compute the probability of x successes, where x <= 3
Now, let's calculate the probabilities for each value of x <= 3:
For x = 0:
P(0) = (9 C 0) * 0.6^0 * (1-0.6)^(9-0)
= (1) * 1 * 0.4^9
= 0.4^9
≈ 0.001572864
For x = 1:
P(1) = (9 C 1) * 0.6^1 * (1-0.6)^(9-1)
= (9) * 0.6 * 0.4^8
≈ 0.04023328
For x = 2:
P(2) = (9 C 2) * 0.6^2 * (1-0.6)^(9-2)
= (36) * 0.6^2 * 0.4^7
≈ 0.12069984
For x = 3:
P(3) = (9 C 3) * 0.6^3 * (1-0.6)^(9-3)
= (84) * 0.6^3 * 0.4^6
≈ 0.214990848
To compute the probability of x <= 3, we sum up the probabilities for each value of x:
P(x <= 3) = P(0) + P(1) + P(2) + P(3)
≈ 0.001572864 + 0.04023328 + 0.12069984 + 0.214990848
≈ 0.377496832
Therefore, the probability of having x <= 3 successes in 9 independent trials, where the probability of success is 0.6, is approximately 0.3775.