Question

Defects on plywood sheet occur at random with the average of one defect per 50 Sq.ft. Find the probability that such a sheet has no defect

Answer 1

Let X denote the number of defects on a plywood sheet.

Given, m = 1, e^–1 = 0.3678

∴ X ~ P(m) ≅ X ~ P(1)

The p.m.f. of X is given by

P(X = x) = `("e"^-"m" "m"^x)/(x!)`

∴ P(X = x) = `("e"^-1 (1)^x)/(x!)`

P(no defects on a plywood)

= P(X = 0)

= `("e"^-1 (1)^0)/(0!)`

= `(0.3678 xx 1)/(1)`

= 0.3678