Probability and statistics
Engineering Mathematics · Engineering
Study notes
A factory has 2% defective rate. In a sample of 100, what's the expected number of defectives and standard deviation? Binomial: n=100, p=0.02. E[X] = np = 2. Var = np(1−p) = 100×0.02×0.98 = 1.96. σ = √1.96 = 1.4. So expect 2 ± 1.4 defectives.