1.1 What is Statisitcs?

Data

systematically recorded info.

• usually used to calculate, analyze, or predict

Statisitcs

study of how to collect, organize, analyze, and interpret data collected from a group

Descriptive Stat.

collecting and organizing data

• describes data using numerical summaries tables, and graphs

Inferential Stat.

analyzing and interpreting collected data.

• Uses sample data to make a statement about what we believe to be true in the population, w/ a certain measure of reliability.

Individual

person or object that you want info. about

Variable

measurement or observation of the individual

Population

set of all values of the variable for the entire group

Sample

a subset form the population

Parameter

A number calculated from the population.

• fixed value

Statistic

a number calculated from the sample

• used to estimate the parameter value

Quantitative Variable

measureable

Qualitative Variable

categorical

Discrete Quan.

things you can count

Continuous Quan.

any value, usually measured

Level of Measurement

determines which statistically calculations are meaningful

Normal data

name/category

• NO order
• NO #’s
  • NO arithmetic

Ordinal data

nominal that can be ordered

• NO arithmetic

Interval data

ordinal that can be added/subtracted

Ratio data

Interval but can be divided