Unit 1 Statistics

statistics

the science and art of collecting, analyzing, and drawing conclusions from data

population

the entire group of items or individuals we want info about

census

collects data from every item or individual in the population

sample

a subset of items or individuals in the population from which we collect data

parameter

a number that describes some characteristic of a population

statistic

a number that describes som characteristic of a sample

observational unit

an item or individual described in a data set or statistical study

variable

a characteristic that can take different values for different observational units

individual

object described in a set of data (can be people, animals, or things)

variable

characteristic that can take different values for different individuals

categorical variables

take values that are labels, placing individuals into categories

quantitative variables

take number values, counts, or measurements

Discrete variable

can take a set of possible values with gaps between them in the number line

Continuous variable

can take any value in an interval on the number line

Distribution

the distribution of a variable tells us what values the var takes and how often it takes each value

Approximately Uniform

if the frequency of each possible value is about the same