Bus Analytics Ch 5

discrete variables

Can only assume a countable number of values.

probability distribution for a discrete variable

is a mutually exclusive list of all possible numerical outcomes for that variable and a probability of occurrence associated with each outcome.

Binomial probability distribution

A fixed number of observations, n.

Each observation is classified into one of two mutually exclusive & collectively exhaustive categories.

• e.g., head or tail in each toss of a coin; defective or not defective light bulb.

Poisson distribution

use when you are interested in the number of times an event occurs in a given area of opportunity.

area of opportunity

na continuous unit or interval of time, volume, or such area in which more than one occurrence of an event can occur.

• The number of scratches in a car’s paint.

• The number of mosquito bites on a person.

• The number of computer crashes in a day