AP Stats Unit 1

Population (N)

The entire group of individuals or items that you want to learn about

Sample (n)

a smaller, manageable subset of individuals or objects chosen from a larger population

Prospective study

A study following data over time

Retrospective study

Uses past records

Categorical Variable

A variable divided into categories or groups

Quantitative Variable

A variable that can be measured or expressed numerically

Marginal relative frequency

The proportion or percentage of individuals in a single specific category relative to the grand total

Joint relative frequency

Uses inside data divided by the grand total

Conditional relative frequency

The proportion or percentage of individuals in a specific category given another category

Association

If knowing the value of one variable helps predict another (If/Then)

Bar Graph & Pie chart

Shows Frequency (how many) or Relative Frequency (percent %)

Segmented Bar Graph

Stacks up categories on bars to make 100%

Mosaic Bar graph

Same as segmented bar graph, but width is is proportional to group size

Quantitative Discrete Data

A countable number of values, often represented as whole numbers. (number of students in a class/number of cars in a parking lot)

Quantitative Continuous Data

Counted through decimals or non-whole numbers (Weight/Height)

Histogram

General values unlike Dot Plots & Stem n’ Leaf plots

Dot Plots

A graphical display that uses dots to represent individual data points along a number line, emphasizing the distribution of small datasets.

Stem & Leaf Plot

A type of graphical display that shows data by splitting each value into a "stem" (the leading digit) and a "leaf" (the trailing digit), preserving the original data while showing its distribution.

Unimodal

A distribution with a single peak

Bimodal

A distribution with two peaks

Multimodal

A distribution with multiple peaks.

Skewed Right

Less data on the right side

Skewed Left

Less data on the left side

Symmetric Distribution

Where left and right sides are mirror images of each other

Uniform Distribution

A probability distribution where all outcomes are equally likely, resulting in a flat shape.

Describing Distribution

Shape/Outliers/Center/Variability + Context (SOCV)

Range

The difference between the maximum and minimum values in a data set, indicating the spread of the data. Maximum—Minimum

Histogram

A graphical representation of the distribution of numerical data, where the data is grouped into bins and the frequency of each bin is shown with bars.

Standard Deviation

Measures the distance of values from the mean in a data set

Standard Deviation Calculation