Answer :
Answer:
0.4204 probability, option b.
Step-by-step explanation:
Exponential distribution:
The exponential probability distribution, with mean m, is described by the following equation:
[tex]f(x) = \mu e^{-\mu x}[/tex]
In which [tex]\mu = \frac{1}{m}[/tex] is the decay parameter.
The probability that x is lower or equal to a is given by:
[tex]P(X \leq x) = \int\limits^a_0 {f(x)} \, dx[/tex]
Which has the following solution:
[tex]P(X \leq x) = 1 - e^{-\mu x}[/tex]
The probability of finding a value higher than x is:
[tex]P(X > x) = 1 - P(X \leq x) = 1 - (1 - e^{-\mu x}) = e^{-\mu x}[/tex]
Children arrive at a house to do Halloween trick-or- treating according to a Poisson process at the unlucky rate of 13/hour
13 arrivals during an hour, which means that the mean time between arrivals, in minutes is of [tex]\mu = \frac{13}{60} = 0.2167[/tex]
What is the probability that the time between the 15th and 16th arrivals will be more than 4 minutes ?
This is P(X > 4). So
[tex]P(X > 4) = e^{-0.2167*4} = 0.4204[/tex]
So the correct answer is given by option b.