1. The problem statement, all variables and given/known data The number of flaws in a plastic panel used in the interior of cars has a mean of 2.2 flaws per square meter of panel . What's the probability that there are less than 20 surface flaws in 10 square meter of panel ? 2. Relevant equations 3. The attempt at a solution This is a poisson distribution problem , am i right ? X ~Po(22) for 10 square meter of panel It's quite insane to calculate the probability from 1 to 20 , right ? I'm wondering is there any appoximation method so that i can solve this question easily ?