AP STATISTICS UNIT 1 TEST

What makes a good investigative question? 

1. Includes the variable of interest (aka what is being measured) 

2. Includes the population (the larger group you want to draw conclusions about) 

3. Compares/ explains the relationship between two variables or estimates a proportion/mean

Bar graphs, frequency tables, and dot plots are used to display

categorical data 

Frequency histograms, stem and leaf plots, and dot plots are used to display

quantitative data

what is the mean going to be for a standardized score distribution

0

what is the SD going to be for a standardized score distribution

1

\when adding/subtracting a constant or multiplying/dividing by a constant for quantitative data what happens to the shape

IT STAYS THE SAME

\when adding/subtracting a constant or multiplying/dividing by a constant for quantitative data what happens to the variability

adding and subtracting it stays the same, multiplying and dividing it multiplies and divides by that number

\when adding/subtracting a constant or multiplying/dividing by a constant for quantitative data what happens to the center

it is going to change by either adding, subtracting, dividing, or multiplying

format for Z-scores

CONTEX is Z-SCORE standard deviations ABOVE/BELOW the mean

what does z-score/standerized score show/explain

• Explains how far off you are from the mean without using units 

• Shows position relative to other values in the distribution

Percentiles

percent of data that is less than or equal to a certain value

what to include when comparing distribution

CSOCS (context, shape, outliers, center, spread) Compare distributions of quantitative data.

INCLUDE CONTEXT AND COMPARATIVE LANGUAGE 

• Data measures … 

• Lower than, equal to, greater than 

• Data A Slightly this while data B is slightly this

5# summary includes

• Min

• Q1- median of lower half

• Median

• Q3 - median of upper half 

• Max

lower outlier

• < Q1-1.5xIQR 

higher outlier

High Outlier > Q3+1.5xIQR

Right Skew

Mean > Median

 Left Skew 

Mean < Median 

Symmetric

Mean = Median

Mean and SD are BLANK to outliers

nonresistant

Median and IQR are BLANK to outliers and skew

resistant

how to make a stem plot

• Group data 

• draw stems (left side)

• Draw leaf (right side) 

• Title 

• Key!!!

comparing proportions/percentages/relative frequencies

“the proportion/percent/relative frequency of [Category A] who [do this/have this/ etc] is [higher/lower] than the proportion/percent/relative frequency of [Category B] who [do this/have this/ etc]”

What three components should you include when describing an association

• Claim

• Support claim by comparing percentages

• Include contex

how to spot a misleading graph

• May not have an axis or scale 

• May cut off the x or y axis, or start at a weird place (doesn’t start at 0 called truncated y axis)) 

• May use pictures for bar graphs

Observational unit

all the people/ things that participated in a study that are being observed without any changes.

Census

a study that collects data from every single member of an entire population

Stratified Sample

divides a diverse population into smaller, non-overlapping groups called strata based on shared characteristics, and then randomly selects samples from each group

Cluster Sample

divide a large population into smaller, naturally occurring groups called clusters

Simple Random Sample

a subset of individuals chosen from a larger population where every single person and every possible combination of people has an equal and fair chance of being chosen

what formula is this

standard deviation formula