stats section 1.1-1.4

for the quiz lol

data

collections of observations. ex: measurements or survey responses

statistics

the collection, analysis, interpretation & the presentation of data

two common descriptive statistics

mean (avrg) & proportion (%)

population

collection of persons, places, things that we are studying

parameter

numerical characteristic that describes the population

sample

a subset or sub-collection of the population

A STATISTIC (singular!)

a numerical characteristic that describes the sample

sampling

process of collecting some of the population

statistical process

ask a question → identify population → take random sample → analyze data → infer the answer for the populationp

variables

denoted by capital letters such as X or Y is a characteristic/measurement that can be determined for each member of the population

numerical variable:

takes on values with equal units

categorical variable:

places each member of the population into a category

quantative (numerical) data

numbers representing counts of measurements

qualitative (categorical) data

consists of names or labels that are not numbers representing counts of measurements

discrete data (ONLY QUANTITATIVE)

number of values is finite or countable

continuous data (ONLY QUANTITATIVE)

where the collection of values is not countable (think decimals)

decision rule for classifying data

1. determine if variable is qualitative or quantitative

   1.5: if quantitative = is it discrete or continuous

variable vs categories

v= general characteristics being measured
c=possible values of that variable

Bar graph

Uses bars of équateur worth to show fréquences of categories of categorical data