A certain type of plastic foil is four feet wide, and has, on average, two ‡flaws in a 100 ft roll. Find the probability that a 20 ft piece has two flaws.
A certain type of plastic foil is four feet wide, and has, on average, two ‡flaws in a 100 ft roll. Find the probability that a 20 ft piece has two flaws.
Help please?
Use the Poisson distribution with $\displaystyle \mu = \frac{2}{100} \times 20 = \frac{2}{5}$.