Random Variables and Probability Distributions
This section first defines discrete and continuous random variables. Then, it introduces the distributions for discrete random variables. It also talks about the mean and variance calculations.
- The probability distribution of a discrete random variable
is a listing of each possible value
taken by
along with the probability
that
takes that value in one trial of the experiment.
- The mean
of a discrete random variable
is a number that indicates the average value of
over numerous trials of the experiment. It is computed using the formula
.
- The variance
and standard deviation
of a discrete random variable
are numbers that indicate the variability of
over numerous trials of the experiment. They may be computed using the formula
, taking the square root to obtain
.