Industrial quality control programs often include inspection of incoming materia
ID: 3180725 • Letter: I
Question
Industrial quality control programs often include inspection of incoming materials from suppliers. If parts are purchased in large lots, a typical plan might be to select 20 parts at random from a lot and inspect them. A lot might be judged acceptable if one or fewer defective parts are found among those inspected. Otherwise, the lot Is rejected and returned to the supplier. Use technology or Appendix Table 9 to find the probability of accepting lots that have each of the following. (a) 5% defective parts P(lot will be accepted) = 0.735 (b). 20% defective parts P(lot will be accepted) = 0.07 (c) 25% defective parts P(lot will be accepted) =Explanation / Answer
Binomial Distribution
PMF of B.D is = f ( k ) = ( n k ) p^k * ( 1- p) ^ n-k
Where
k = number of successes in trials
n = is the number of independent trials
p = probability of success on each trial
P( X < = 1) = P(X=1) + P(X=0)
= ( 20 1 ) * 0.25^1 * ( 1- 0.25 ) ^19 + ( 20 0 ) * 0.25^0 * ( 1- 0.25 ) ^20
= 0.024