UPDATED The Practice of Statistics, 6e, Chapter 1 -- DUMB EDITION

more straightforward definitions / examples from the book. basically my notes but i don't want to write them

individual

individual

people, animals, things that are being studied - usually in the question and not the table

variable

characteristic that changes from one individual to another

categorical data

values that are group/labels, can’t take average of them

quantative data

numerical values, can count and take average of

discrete variable

quantitative variable that’s a fixed set with gaps in data, basically can’t have decimals

ex: number of languages spoken (can only speak 1, 2 or 3, not 2.5)

continuous variable

quantitative variable that can take any value in an interval, basically can take decimals and fractions

ex: height

distribution

what values the variable takes/how often it takes those values

frequency table

number of individuals having each value (the numbers you see in the table)

relative frequency table

proportion/percent of individuals having each value (have to do math for this)

marginal relative frequency

part/every individual

ex: proportion of people in the sample who never used a snowmobile

proportion

number between 0 and 1

percent

number between 0 and 100 - multiply proportion by 100

conditional relative frequency

key word: given, of

ex: what proportion of environmental club members in the sample are snowmobile owners?

join relative frequency

key word: and

ex: proportion of people in the sample are not environmental club members and never use snowmobiles

side by side bar graph

segmented bar graph

mosaic plot

association

knowing one variable helps us predict the value of the other

core (explanatory variable, x-value, input) predict elective (response variable)

ex: club members more like to rent or own a snowmobile