characteristics of a probability distribution
1. the probability of a particular outcome is between 0 and 1 inclusive. 2. the outomes are mutually exclusive events. 3. the list is exhaustive so the sum of probabilities of the various events is equal to one.
discrete random variable
it can assume only certain clearly separated values. it is usually the result of counting something
continuous random variable
can assume an infinite number of values within a given range. it is usually the result of some type of measurement.
features of a discrete distribution
1. the sum of probabilities of the various outcomes is 1. 2. the probability of a particular outcome is between 0 and 1. 3. the outcomes are mutually exclusive.
a mean is a typical value used to represent the central location of a probability distribution. it is also referred to as its expected value (U = E[xP(x)])
formula for finding mean
U = E(xP(x)]
formula for standard variance
define standard variance
measures the amount of spread in a distribution