Answer:
0.36427
Step-by-step explanation:
Mean = λ = 18 messages per hour
P(X = x) = (e^-λ)(λ⁻ˣ)/x!
P(X ≤ x) = Σ (e^-λ)(λ⁻ˣ)/x! (Summation From 0 to x)
But the probability required is that the messages thay come in an hour is between 15 and 20, that is, P(15 < X < 20)
P(15 < X < 20) = P(X < 20) - P(X ≤ 15)
These probabilities will be evaluated using a cumulative frequency calculator.
P(X < 20) = 0.65092
P(X ≤ 15) = poissoncdf(18, 15) = 0.28665
P(15 < X < 20) = P(X < 20) - P(X ≤ 15) = 0.65092 - 0.28665 = 0.36427.
You can use the Poisson distribution calculator here
https://stattrek.com/online-calculator/poisson.aspx
Answer:14
Step-by-step explanation:
The correct answer for this will be a because you can times them together hope this helps
I think 11 is yes, if the parent is 40 and the child is 20. (and they had kids when they were young) 12 is yes, if the parent is 30 and the child is 10. 13 is yes, if the parent is 60 and the child is 40. unlikely though, but who cares. 14 is no, the parent would have been really young when they gave birth to the child. like 10.
