In a Poisson probability problem, the rate of errors is one every two hours.To find the probability of three defects in four hours,
A) = 1, x = 4
B) = 2, x = 3
C) = 3, x = 2
D) $\mu$ = 3, x = 6

Question

In a Poisson probability problem, the rate of errors is one every two hours.To find the probability of three defects in four hours, 
A) = 1, x = 4 
B) = 2, x = 3 
C) = 3, x = 2 
D) $\mu$ = 3, x = 6

Quizplus · Accepted Answer

We use the Poisson probability formula: P(x events in t time) = (e^(-rt))*(rt)^x / x!, where r is the rate of events, t is the time, and x is the number of events we want to find the probability of. 
In this case, r=1/2 (since the rate is one error every two hours), t=4 hours (since we want to find the probability of three defects in four hours), and x=3 (since we want to find the probability of three defects). 
Plugging in these values, we get: P(3 defects in 4 hours) = (e^(-2))*(2)^3 / 3! = 0.180447. 
The closest choice to this answer is B, which gives the correct value of r and x, but has the wrong values for t and μ.

In a Poisson Probability Problem, the Rate of Errors Is μ\muμ

In a Poisson Probability Problem, the Rate of Errors Is $\mu$