# Shared Flashcard Set

## Details

Statistic Definitions
definitions
25
Mathematics
01/26/2009

Term
 Variable
Definition
 characteristics or attributes that can assume different values. A generalization unknown quantity "X"
Term
 Data
Definition
 measurements of observations collected now or in the past
Term
 Random Variable
Definition
 a variable selected in a random fashion"values determined by chance..."
Term
 Discrete Variable
Definition
 assumes a singular value, counted, {Fixed #}-things we can count
Term
 Continuous Variable
Definition
 A value that falls within some range, measured x: temp, length, time
Term
 Qualitative Data
Definition
 descriptions- not calculatedex: Name, address, phone #, SSN
Term
 Quantitative Data
Definition
 has a dimension and is used for calculationsex: height, weight, length, \$\$
Term
 Nominal
Definition
 means 'to give a name to'ex: zipcode, sex, political party, major study
Term
 ordinal
Definition
 things we classify in some order ex: (A-F), rankings, (1st, 2nd,....), first letter of last name
Term
 Internal Level
Definition
 ranked and ordered infoex: difference in SAT scores, I.Q, Temps
Term
 Ratio level
Definition
 measurements expressed as ratiosex: height 2x taller, time 4x faster
Term
 populations
Definition
 Large, large numbersex: set of all men 20-25, all cars made in 1993-hard to work with
Term
 Samples
Definition
 A Large sample greater than or equal to 30a small sample is less than 30-easier to work with
Term
 Descriptive Stats
Definition
 The organized and summarized data calculated/ presented as1. Tables of Data2. Graphs3.Charts
Term
 Inferential Stats
Definition
 Use samples to make estimations or a supposition abut a population
Term
 Random Sample
Definition
 Everyone has an equal chance of being selected. If you replace its not completely random, only if u put back whatever you draw.
Term
 Stratified Sample
Definition
 Selecting members from each segment of a population.Strata- population divided into subsets i.e. income, age, race, gender, etc.
Term
 Cluster Sample
Definition
 When a population falls into a natural subset of the population (geographic)
Term
 Systematic sample
Definition
 A developed (schemed) way of selecting from a population i.e. 1st, 3rd, 5th, ect., of population even, odd, every 10th, etc.
Term
 Convenience Sample
Definition
 Sampling the available people or items for a study--this can lead to a biased study
Term
 Blind Study
Definition
 Patient does not know whether they are getting medicine or placebo
Term
 Double Blind
Definition
 neither patient nor doctor knows who is getting what
Term
 Census
Definition
 Data collected from entire population.population of employees, US census 2010
Term
 Simulation
Definition
 when studies are too large, impractical or dangerous--crash tests
Term
 Sampling
Definition
 testing a select group of people
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