Chapter 1 Flashcards
Population
The overarching set of all individuals which we want to study.
Sample
A subset of a population on which we gather data that can be used to make inferences about a population.
Census
Gathering data on each individual within a population
Parameter
A numerical value summarizing the population data (mean, median, mode, range, maximum, etc.) The value of the parameter is usually unknown.
Statistic
A numerical value summarizing the sample data (sample mean, median, mode, range, etc.)
Data
Information, numerical or qualitative gathered through experiments and surveys.
Subject
An individual within a sample.
Variables
The features that we measure about the subjects.
Quantitative variables
numerical data that gives us some quantity.
Categorical variables
Variables that sort and organize the data into different categories or classifications.
The Statistical Method (Three Steps)
1) Design
2) Description
3) Inference
Design
Refers to how the data is obtained. Valid inferences cannot be made without a good design.
Description
The summarizing of data obtained. (Providng the mean or percentage, creating a bar graph or pie chart, etc.)
Inference.
Making decisions or predictions based on the data.
μ
Mu. Population mean (parameter)
́x
X-bar Sample mean (statistic)
P
P. Population proportion (parameter)
p
p-hat. Sample proportion
Proportion
Another way to express a percentage. Must be between 0 and 1.
Satistics
The art and science of designing studies and analyzing data that those studies produce.
What is the ultimate goal of statistics?
Translating the data into knowledge and understanding of the world around us.
Four steps of satisitcs
1) Formulate a statistical question. 2) Collect data. 3) Analyze data. 4) Interpret results.
Probability
A framework for quantifying how likely various outcomes are.
Random sampling
Selecting subjects randomly to create a good reflection of the population at large. Very likely to fall withing 5 percentage points of the actual population.
