In the lecture slide talking about the mean or expected value, why do we use the symbol of population mean if we are not conducting a census? Why not the sample mean? Explain briefly.

1. Probability distributions 1.2 Metrics . The mean or expected value of a random variable, in a probability distribution, is the theoretical (long-run) average of the variable. . Generalized formula for mean (u) or expected value [E(X)]: U = X . P(X ) +X, . P(X, ) +X, . P(X, ) + .. . +X . P(X ,, ) n CANVAS (uf EX, . P(X, ) i=1 Why do we use, in this case, u, which is the population mean? Why or... n not the sample mean? Tell us in E(X) the Lecture 5 - Within-lecture X, . P(X;) quiz! i=1