ABC Paper Corporation manufactures a special grade of lamina

ABC Paper Corporation manufactures a special grade of laminated (plastic coated) paper. For the current process being used, the quality control staff has shown that, on average, one defect in the lamination can be expected in every 1.25 square feet of laminated paper.

A. A square foot of the product is randomly selected for inspection after the coating process. What is the chance that there is at least one defect in this area?

B. What is the chance that in the next five square feet of laminated paper, half as many defects will be found as expected?

Solution

For every 1.25 sq ft paper 1 defect

Hence for every 1 sq ft paper defect = 1/1.25 = 0.8

X no of defects is Poisson with mean = 0.8

A) P(X=0) = 0.4493

B) For 5 sq ft expected value = 4

Reqd prob = P(X=2) = 0.1465