STT 212 Chapter Notes - Chapter 6: Mandala 2, Random Variable, Weighted Arithmetic Mean

• School: University of Rochester
• Department: Statistics
• Course: STT 212
• Professor: Mcdermott

Document Summary

Random variable a numeric outcome of a chance experiment. Discrete rv has possible values that are isolated points on a number line. Probability distribution for a discrete rv specifies all possible values that the random variable can take on along with its corresponding probability. The probabilities must sum to 1: x (one category) is quantified to find a frequency table called a probability histogram. The mean of a discrete rv: simply a weighted average, x = e(cid:894)x(cid:895) = xp(cid:894)x(cid:895) The standard deviation of a discrete rv: x= ( (x- x)2p(x)) Binomial experiment: n identical trials, only two possible outcomes: success or failure, the same probability of success for each trial. Binomial rv: the number of successes in a binomial experiment: x ~ bin(n,p, n = number of trials, p = probability of success. The probability distribution of a binomial rv: (cid:4666)=(cid:4667)= !