A Student's Guide to Descriptive Statistics

Data organization

is the process of sorting and arranging raw data to make it more meaningful and useful for analysis.

Raw Data

Scattered, unorganized facts and figures

Organized Data

Structured information revealing patterns

Frequency Distributions

Understanding how often values occur and organizing data into meaningful categories

Class Intervals

Grouping data for clearer insights and creating organized frequency distributions

Stem-and-Leaf Plots

Preserving raw data while showing distribution in a visual and organized manner

Graphical Representations

Visualizing data with various powerful tools to communicate insights effectively

frequency

distribution is a statistical tool that organizes raw data to show how often each value or category occurs within a dataset.

Categorical Frequency Distribution

is used when data can be sorted into distinct categories or classes, such as nominal or ordinal data.

Grouped Frequency Distribution

A method of organizing numerical data that spans a wide range of values by grouping them into class intervals.

Determining Number of Classes

When working with numerical data that spans a wide range, we need to group data into classes to create a manageable frequency distribution.

Class limits

define the range of values in each class, while class boundaries are the real numbers that separate classes.

Stem-and-Leaf Plot Basics

A powerful tool for visualizing the shape of a distribution while retaining the original data values.

Histogram Construction

A graphical representation of frequency distribution using adjacent bars to show the distribution of quantitative data.

Frequency Polygon Creation

A line graph that connects the midpoints of class intervals to show the shape of a distribution.

Cumulative Frequency 

The sum of frequencies up to a specific class interval. It shows how many data points fall below the upper boundary of each class.

Ogives

Cumulative frequency curves that display an S-shaped pattern, showing the progressive accumulation of data.

Pareto Chart

A specialized bar chart that displays categories in descending order of frequency, combined with a line graph showing cumulative percentage.

Pie Chart

A circular graph divided into slices, where each slice represents a proportion of the whole.

scatter plot

is a graph that displays the relationship between two numerical variables. Each point represents an observation with its position determined by the values of the two variables.

Time Series Graphs

A graph that displays data points collected over regular time intervals to identify trends, patterns, and seasonal variations.

pictograph

uses pictures or symbols to represent quantities of data, making information more accessible and visually engaging for audiences.