question 19 if the probability of success in a binomial experiment is 0.8 and the probability of failure is…

question 19 if the probability of success in a binomial experiment is 0.8 and the probability of failure is consequently 0.2, what is the probability of getting at least one success in 3 trials? a 0.728 b 0.488 c 0.512 d 0.120
Answer
Explanation:
Step1: Use complementary - probability formula
The probability of getting at least one success is equal to 1 minus the probability of getting no successes.
Step2: Calculate the probability of no successes
In a binomial experiment, the probability of (k = 0) successes in (n=3) trials with probability of failure (q = 0.2) is given by the binomial - probability formula (P(X = k)=C(n,k)\times p^{k}\times q^{n - k}), where (C(n,k)=\frac{n!}{k!(n - k)!}). When (k = 0), (n = 3), (p=0.8), and (q = 0.2), we have (P(X = 0)=C(3,0)\times(0.8)^{0}\times(0.2)^{3}). Since (C(3,0)=\frac{3!}{0!(3 - 0)!}=1) and ((0.8)^{0}=1), then (P(X = 0)=1\times1\times0.008 = 0.008).
Step3: Calculate the probability of at least one success
Let (P(X\geq1)) be the probability of at least one success. Then (P(X\geq1)=1 - P(X = 0)). Substituting (P(X = 0)=0.008) into the formula, we get (P(X\geq1)=1 - 0.008=0.992). There seems to be an error in the problem - setup or options provided. If we assume the probability of success (p = 0.2) and probability of failure (q = 0.8):
Step1: Use complementary - probability formula
The probability of getting at least one success is (P(X\geq1)=1 - P(X = 0)).
Step2: Calculate the probability of no successes
Using the binomial - probability formula (P(X = k)=C(n,k)\times p^{k}\times q^{n - k}), with (n = 3), (k = 0), (p = 0.2), (q = 0.8), (C(3,0)=\frac{3!}{0!(3 - 0)!}=1), (P(X = 0)=C(3,0)\times(0.2)^{0}\times(0.8)^{3}=1\times1\times0.512 = 0.512).
Step3: Calculate the probability of at least one success
(P(X\geq1)=1 - P(X = 0)=1 - 0.512 = 0.488)
Answer:
B. 0.488