AP Stats Flashcards
categorical variable
labels that place each individual into a particular group
ex: race, sex, age group
quantitative
takes number values that are quantities, counts, or measurements
ex: height, weight, cost
quantitative discrete
a fixed set of possible values
ex: how many green marbles you draw out of a bag
quantitative continuous
any value in an interval on the number line
ex: time
relative frequency table
shows the proportion or percent of individuals having each value.
two-way table
a table of counts that summarizes data on the relationship between two categorical variables for some group of individuals.
categorical graphs
- Pie Charts
- Pictographs
- Dot-plots
- Bar Graphs
- Side-by-side Bar Graphs
- Segmented Bar Graphs
- Mosaic Plots
Association
if knowing the value of one variable
helps us predict the value of the other
Simpson’s Paradox
a contradiction between what we see when looking at individual
categories and the subtotals for our distributions when dealing with categorical
variables
Quantitative Graphs
- Dot-plots
- Stem-plots
- Histogram
- Boxplots
- Ogives
how we describe distributions
CUSS + BS
-C: center
-U: unusual outliers
-S: spread
-S: shape
-BS: be specific
mean
average of all individual data values
Statistic
a number that describes some characteristic of a sample
-ex: asking 20 random people their height and averaging results
Parameter
a number that describes some characteristic of a population
-ex: asking everyone in the population
their height and averaging results
Range
difference between the maximum value
and the minimum value
Standard Deviation
the typical or average distance of the values in a distribution from the _mean
Interquartile Range (IQR)
IQR = Q3 – Q1
lower Outlier Test
Lower Outliers < Q1 – 1.5(IQR)
higher outlier test
Higher Outliers > Q3 + 1.5(IQR)
response variable
measures an outcome of a study
explanatory variable
may help predictor explain changes in a
response variable
population
the entire group we want to know about