The probabilities are 0.1323, 0.247, 0.185 and 0.98.
The probability of obtaining a specific number of successes (X) in a binomial distribution can be calculated using the formula:
![\[ P(X) = \binom{n}{X} * p^X * (1 - p)^(n - X) \]](https://img.qammunity.org/2024/formulas/mathematics/high-school/6pmxqtv3k3ptyrc107zc5l0strwie5n1jk.png)
Let's calculate each probability:
(a) For n = 5, p = 0.3, and X = 3:
![\[ P(X) = \binom{5}{3} * 0.3^3 * (1 - 0.3)^(5 - 3) \]](https://img.qammunity.org/2024/formulas/mathematics/high-school/3u3c1g3ilrl1lhl64ljaf4vvr6a87f9c6s.png)
P(X) = 10 x 0.027 x 0.49
P(X) = 0.1323
(b) For n = 7, p = 0.7, and X = 6:
![\[ P(X) = \binom{7}{6} * 0.7^6 * (1 - 0.7)^(7 - 6) \]](https://img.qammunity.org/2024/formulas/mathematics/high-school/letz4xn3xz8aod33m60646m3w86hod5zjf.png)
P(X) = 7 x 0.117649 x 0.3
P(X) = 0.247
(c) For n = 15, p = 0.2, and X = 4:
![\[ P(X) = \binom{15}{4} * 0.2^4 * (1 - 0.2)^(15 - 4) \]](https://img.qammunity.org/2024/formulas/mathematics/high-school/8ptbpal6qprckguocc6kc1tjmifyh61l1s.png)
P(X) = 1365 x 0.0016 x 0.1073741824
P(X) = 0.185
(d) For n = 18, p = 0.6, and X = 7:
![\[ P(X) = \binom{18}{7} * 0.6^7 * (1 - 0.6)^(18 - 7) \]](https://img.qammunity.org/2024/formulas/mathematics/high-school/z76wpd4nbncwj958jnfm5xujbgsa7url9j.png)
P(X) = 31824 x 0.027 x 0.1073741824
P(X) = 0.98
These are the calculated probabilities for each scenario (a), (b), (c), and (d) using the binomial distribution formula.