# Statistics Flash Cards

Topics: Probability theory, Random variable, Discrete probability distribution Pages: 16 (2977 words) Published: February 2, 2013
Term
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...