STA 2023 Lecture Notes - Lecture 22: Random Variable, Standard Deviation, Sample Space
Document Summary
A random variable is a variable whose values are determined by chance. A discrete probability distribution consists of the values a random variable can assume and the corresponding probabilities of the values. The sum of the probabilities of all events in a sample space adds up to 1. Each probability is between 0 and 1, inclusively. Construct a probability distribution for the data and draw a graph for the distribution. The probabilities that a patient will have 0,1,2, or 3 medical tests performed on entering a hospital are 6/15, 5/15, 3/15, and 1/15 respectively. The mean, variance, and standard deviation should be rounded to one more decimal place than the outcome x. When fractions are used, they should be reduced to lowest terms. The probability that a cellular phone company kiosk sells x number of new phone contracts per day is shown below. Find the mean, variance, and standard deviation for this probability distribution.
