Final answer:
To find P(r = 0), use the binomial probability formula. To find P(r ≥ 1), use the complement rule.
Step-by-step explanation:
(a) To find P(r = 0), we need to calculate the probability of getting 0 successes in 7 trials. The formula for the probability of getting exactly r successes in n trials is:
P(r) = (n choose r) * p^r * (1 - p)^(n - r)
Plugging in the values, we have:
P(0) = (7 choose 0) * 0.30^0 * (1-0.30)^(7-0) = 1 * 1 * 0.7^7 = 0.0058 (rounded to three decimal places).
(b) To find P(r ≥ 1) using the complement rule, we need to calculate the probability of getting at least 1 success in 7 trials. The complement rule states that P(A') = 1 - P(A). So, P(r ≥ 1) = 1 - P(r = 0). Plugging in the value from part (a), we have:
P(r ≥ 1) = 1 - P(0) = 1 - 0.0058 = 0.9942 (rounded to three decimal places).