# Statistics Vocab Chapter 1, 2, 3

## Terms

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Quantitative Variable
age, height, weight, temperature
Qualitative Variable
Characteristics- gender, religious preferance, geographic location
Discrete Variables
Can be counted
Continuous Variables
can assume all values between any 2 specific values- obtained by measuring
Data<qualitative or quantitative
Quantitative<Discrete or Continuous
Descriptive Statistics
collection, organization, summarization, and presentation of data: census-average age, income, or other characteristics of US population
Inferential Statistics
make inferences from sample to populations: uses probability-

Generalizing from samples to populations, estimations and hypothesis tests, relationships and predictions
Nominal level measurement
mutually exclusive exhausting categories in which no order or ranking can be imposed on the data: zip code, gender, eye color, political affiliation, major field, nationality
Ordinal level measurement
categories that can be ranked: grades, 1st 2nd place, rating scale(poor, good), ranking of tennis players
Interval level measurement
ranks data - no zero: SAT score, IQ, Temperature
Ratio level measurement
lift twice as much, height weight, time, salary, age

true zero
Random Sample
chance methods, random numbers, table of random numbers
Systematic Sample
numbering then selecting everty kth subject
Stratified Sample
dividing poplulation into groups then selecting from each group
Cluster Sample
intact group representative of the population
Quasi-experimental study
intact groups when random assignment is not possible
Hawthorne Effect
Participants change behavior because they knew they were being tested
frequency distribution
organization of raw data in table form using classes and frequencies
3 types of frequency distribution
categorical and grouped and ungrouped
class midpoint
X= lower boundary + upper boundary /2
Histogram
contigious vertical bars
Frequency Polygon
lines between midpoints
Ogive
graph that represents cumulative frequencies
Relative Frequency graph