**Background:** The weak law of large numbers states that for a sequence $X_1,X_2,\ldots,X_n$ of iid RVs, with expectation $\mu$ and variance $\sigma^2$, the sample mean $\hat{X}=\frac{\sum_{i=1}^nX_i}{n}\stackrel{p}{\rightarrow}\mu$. That is the sample mean converges in probability to the population mean as the number of RVs approaches $\infty$. **Question:** How can you obtain infinitely many iid random variables from a finite population? How do you in practise check that your random variables are independent? **Edit:** By finite population I mean that you consider a population of individuals. This population is finite. You conisder a characteristic in the population. You model the characteristic with a random variable.