Respuesta :
Answer:
A. 0.000045
B. 0.010336
C. 0.082085
D. 0.917915
Step-by-step explanation:
A. Compute the probability of no arrivals in a one-minute period.
P(x=o) = 0.000045
B. Compute the probability that three or fewer passengers arrive in a one-minute period.
p(x = 3) = 0.007567
p(x = 2) = 0.002270
p(x = 1) = 0.000454
p(x ≤ 3) = 0.000045 + 0.007567 + 0.002270 + 0.000454 = .010336
C. Compute the probability of no arrivals in a 15-second period.
p(x = 0) = 0.082085
D. Compute the probability of at least one arrival in a 15-second period.
p(x ≥ 1) = 1.0 - 0.082085 = 0.91791561
Answer:
a) 0.000335
b) 0.0424
c) 0.8751
d) 0.1248
Step-by-step explanation:
This is the case of Poisson's Distribution. Here,
μ = mean = 8 passengers/min
The Poisson's formula is:
P(X) = (e^-μ)(μ^x)/(x!)
a)
For no arrival x= 0
P(X = 0) = (e^-8)(8^0)/(0!)
P(X = 0) = 0.000335
b)
For probability of three or fewer, X ≤ 3
P (X ≤ 3) = ∑[(e^-8)(8^x)/(x!)] (from x = 0 to x = 3)
P (X ≤ 3) = 0.0424
c)
Now, for second time we convert the mean to seconds:
μ = mean = (8 passengers/min)(1 min/60 sec)
μ = mean = 0.13333 passengers/sec
For no arrival x= 0
P(X = 0) = (e^-0.13333)(0.13333^0)/(0!)
P(X = 0) = 0.8751
d)
For at least one arrival X ≥ 1
P(X ≥ 1) = 1 - P(X = 0)
P(X ≥ 1) = 1 - 0.8751
P(X ≥ 1) = 0.1248