Chapter 1 Flashcards
What are the four steps of Statistical Inquiry?
- Question - question to be answered for study
- Design - plan or experiment to generate desired data
- Description - summarizing patterns in raw data
- Inference - making conclusions applicable to population
What is important about the Design?
That it is objective and its variables are diversified
Subject (Individual)
Unit on which we make observations or measurements and collect data
Population
Set of all subjects of interest
Sample
Subset of population on which data is actually collected
Random Variable
A numerical measurement of the outcome of a random phenomenon
What is an example of a Random Variable relative to a presidential election?
1 - Republican Candidate, 0 - Democratic Candidate
Parameter
Numerical summary of population describing its characteristics, generally considered an unknown quantity
When can one calculate a Parameter?
Only when we have information from the whole population
What is an example of a Parameter?
Percent of all likely voters who voted for a Democratic Candidate after an election is held
Statistic
Numerical summary of a sample that describes the sample
How are Parameters of a Population estimated?
By using an analogous sample statistic
Parameter:Population
Statistic:Sample
What is the link between random variables and sample statistics?
Before a sample is collected a sample statistic is a random variable whose value is unknown, but once the sample is collected the value becomes known
Generalization of random variable and sample statistic relationship to general observations
An observation is a random variable before it is observed but after it is observed it loses its randomness and becomes a true observation
