Find the probability

It has been observed that the number of defects in the finish of a surface has an overage of 0.45. What is the probability of a randomly selected item having more than 1 defect in the surface finish?

OPTIONS

• 0.45
• 0.2869
• 0.05
• 0.0755

ANSWER

0.0755

EXPLANATION

The Poisson distribution is used to model rates. The probability of exactly r events occurring can be computed using the poisson distribution. We need to find out probability of exactly 0 and 1 defects and then subtract from 1. Entering the data in Poisson distribution equation gives the probability of exactly zero defects as 0.6376 and for exactly 1 defect as 0.2869. To calculate more than 1 defect, 1-(0.6376+0.2869) = 0.0755