Section 6.1Summary

1. Section 6.1 introduces the idea of random variables, which are variables whose value is determined at least partly by chance. Discrete random variables take values that are either finite or countable and may be put in a list. Continuous random variables take an infinite number of possible values, which is represented by an interval on the number line.
2. Discrete random variables can be described using a probability distribution, which specifies the probability of observing each value of the random variable. Such a distribution can take the form of a table, graph, or formula. Probability distributions describe populations, not samples.
3. We can calculate and interpret the mean , standard deviation , and variance of a discrete random variable using formulas.