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:
787
Step-by-step explanation:
i took the test
Answer:
212 children, and 265 adults
Step-by-step explanation:
To find the number of children and adults, we can set up a systems of equations.
x= number of children
y= number of adults
Equation 1: Price
1.50x+2.25y=914.25
Equation 2: Total number of people
x+y=477
Now, let's solve the equation using substitution.
Rearrange the second equation to solve for one variable.
x+y=477
x=477-y
Now plug x equals into the first equation, and solve for y.
1.50x+2.25y=914.25
1.50(477-y)+2.25y=914.25
715.5-1.50y+2.25y=914.25
715.5+0.75y=914.25
0.75y=198.75
y=265
We just solved for the number of adults. Now let's plug y equals into the second equation to find the number of children.
x+y=477
x+265=477
x=212
Answer:
102 an hour
Step-by-step explanation:
all you do is add all of them together