Answer:
Our total amount value is $4.86.
Step-by-step explanation:
The total amount given is $30.
Now 8 % of $30 = 
or, 8% of $30 = $2.4
Now adding $30 and $2.4,
$ 30 + $2.4 = $32.4
Finding 15% of the total $32.4,
we get 
or, 15% of $32.4 = $4.86
hence, our total amount value is $4.86.
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
One of many outfits mean twice as much