The number of surface flaws in a plastic roll used in the interior of automobile
ID: 3543311 • Letter: T
Question
The number of surface flaws in a plastic roll used in the interior of automobiles has a Poisson distribution with a mean of 0.09 flaw per square foot of plastic roll. Assume an automobile interior contains 10 square feet of plastic roll. Round your answers to four decimal places (e.g. 98.7654).
(a) What is the probability that there are no surface flaws in an auto
Explanation / Answer
then the mean flaw of the automobile interior is found by these expression:
mean flaw = 0.09 * 10 = 0.9
the formula for the Poisson distribution is:
P(x = k) = f(k) = (m^k e^(-m) / k!) .... here m is the mean .
thus
A . P(X = 0) = (0.9^0 e^(-.9) / 0!) = e^(-.9)
B. none of the cars have any surface flaw:
P(X = 0)^11 = e^(-.9)^11 = 0.00005
C. probability that at most one car has a surface flaw:
11 [P(X = 0)]^9 [1 - P(X = 0)]^3 + [P(X = 0)]^11