Answer: the probability that we observe 4 cracks when inspecting a 3 m2 section is 0.034
Step-by-step explanation:
The formula for poisson distribution is expressed as
P(x = r) = (e^- µ × µ^r)/r!
Where
µ represents the mean of the theoretical distribution.
r = x represents the number of successes of the event(cracks).
From the information given,
µ = 3 cracks per 1 m² section
It means that for a 3 m² section of the aircraft, the average number of cracks would be 9
the probability that we observe 4 cracks when inspecting a 3 m2 section would be
P(x = 4) = (e^- 9 × 9^4)/4!
P(x = 4) = 0.034