Final answer:
The probability of exactly five hits between 8:17 P.M. and 8:22 P.M. is approximately 0.0847. The probability of fewer than five hits is approximately 0.0512. The probability of at least five hits is approximately 0.9488.
Step-by-step explanation:
To compute the probability of each scenario, we can use the Poisson distribution formula.
(a) To find the probability of exactly five hits between 8:17 P.M. and 8:22 P.M., we can use the formula P(X = k) = (e^(-λ) * λ^k) / k!, where λ is the average rate of hits per minute and k is the desired number of hits. In this case, λ = (1.3 hits/minute) * (5 minutes) = 6.5. Plugging the values into the formula, we get P(X = 5) = (e^(-6.5) * 6.5^5) / 5! ≈ 0.0847. So, the probability of exactly five hits is approximately 0.0847.
(b) To find the probability of fewer than five hits, we can sum the probabilities of getting 0, 1, 2, 3, or 4 hits. Using the Poisson distribution formula, we can calculate each individual probability and sum them up. Plugging the values into the formula, we get P(X < 5) ≈ (e^(-6.5) * 6.5^0) / 0! + (e^(-6.5) * 6.5^1) / 1! + (e^(-6.5) * 6.5^2) / 2! + (e^(-6.5) * 6.5^3) / 3! + (e^(-6.5) * 6.5^4) / 4! ≈ 0.0512. So, the probability of fewer than five hits is approximately 0.0512.
(c) To find the probability of at least five hits, we can subtract the probability of getting fewer than five hits from 1. Using the Poisson distribution formula, we can calculate the probability of getting fewer than five hits (as calculated in part b) and subtract it from 1. Plugging the values into the formula, we get P(X ≥ 5) ≈ 1 - P(X < 5) ≈ 1 - 0.0512 ≈ 0.9488. So, the probability of at least five hits is approximately 0.9488.