Question

twenty sheets of aluminum alloy were examined for surface flaws. the frequency of the number of sheets with a given number of flaws per sheet was as follows:
number of flaws frequency
0 4
1 3
2 5
3 2
4 4
5 1
6 1
what is the probability of finding a sheet chosen at random which contains 3 or more surface flaws?
which distribution best describes the above scenario?
askcuddy
poisson
binomial
hypergeometric

Explanation:

Step1: Sum frequencies for ≥3 flaws

Frequencies: 3 flaws=2, 4=4, 5=1, 6=1 → Total=2+4+1+1=8

Step2: Calculate probability

Probability = $\frac{\text{Total frequency for ≥3 flaws}}{\text{Total sheets}} = \frac{8}{20} = 0.4$

Step3: Identify distribution

Poisson models rare events (flaws) in fixed unit (sheet).

Answer:

Probability: 0.4
Distribution: A. Poisson