Random Variable

Definition

A variable that takes on different numerical values based on chance

Term

Discrete Random Variable

Definition

A random variable that can only assume a finite number of values or an infinite sequence of values such as 0,1,2,3....

Term

Continuous Random Variables

Definition

Random variables that can assume any vallue in an interval.

Term

Expected Value

Definition

The mean of a probability distribution. the average value when the experiment that generates values for the random variables is repreated over the long run.

Term

Binomial Probability Distribution characteristics

Definition

A distribution that gives the probability of x successes in n trials in a process that meets certain conditions.

Term

Binomial Prob. Dist. characteristics #1

Definition

a trial has only two possible outcomes; a success or a failure.

Term

Binomial Prob. Dist. characteristics #2

Definition

There is a fixed number, n, identical trials.

Term

Binomial Prob. Dist. characteristics #3

Definition

The trials of the experiment are independent of each other. this means that if one outcome is a success, this does not influence the chance of another outcome being a success.

Term

Binomial Prob. Dist. characteristics #4

Definition

The process must be consistent in generating successes and failures. that is, the probability. p, associated with a success remains constant from trial to trial.

Term

Binomial Prob. Dist. characteristics #5

Definition

if p represents the probability of a success, then (1-p) = q is the probability of a failure.

Term

Hypergeometric distribution

Definition

is formed by the ratio of the number of ways an event of interest can occur over the total number of ways any event can occur.

Term

The binomial Dist. is useful when...

Definition

it is useful when the value of a discrete random variable is based on independent trials and when on a given trial there are two possible outcomes and we can count the number of successes and failures.

Term

Poisson Dist.

Definition

Deals with situations in which the trials are independent but we are able to count only the sucesses.

Term

Hypergeometric dist.

Definition

applies when the trials are dependent and the sample size is large relative to the size of the finite population.

Term

False

Definition

True/False: if a random variable is discrete, it means that the outcome for the random variable can take on only one of two possible values.

Term

True

Definition

True/False: the random variable, number of customers entering a store between 9AM and noon, is an example of a discrete random variable.

Term

True

Definition

True/False: When a single value is randomly chosen from a discrete distribution, the different possible values are mutually exclusive.

Term

False

Definition

True/False: The Colbert Real Estate Agency has determined the number of home showings given by its agents is the same each day of the week. then the variable-number of showings-is a continuous dist.

Term

True

Definition

True/False: The time required to assemble two components into a finished part is recorded for each employee at the plant. the resulting random variable is an example of a continuous random variable.

Term

False

Definition

True/False:The Cromwell company has the opportunity to enter into a contract to build a mountain road. the following table shows the probability for the profit that could occur if they ta0ke the contract: profit probability

$30,000_0.15

$50,000_0.20

$70,000_0.30

$100,000_0.35

Based on this info. the expected profit for the company if they take the contract is $60,000.

Term

False

Definition

True/False: a prob. dist. with an expected value greater than the expected value of a second prob. dist. will also have a higher stand. dev.

Term

True

Definition

True/False: the number of...