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Representing a Quantitative Variable with Graphs

Jackson Hernandez

Jackson Hernandez

7 min read

Study Guide Overview

This study guide covers visualizing quantitative data in AP Statistics. It reviews discrete and continuous variables and then details graphical displays: histograms, frequency polygons, ogives (cumulative graphs), stem-and-leaf plots, and dotplots. The guide also includes key vocabulary, exam tips, common mistakes, practice questions, and a scoring breakdown.

AP Statistics: Visualizing Quantitative Data - Your Night-Before-the-Exam Guide ๐Ÿ“Š

Hey there, future AP Stats superstar! Let's get you prepped and confident for tomorrow's exam. We're diving into how to display quantitative data, making sure you can nail those questions with ease. Remember, quantitative data is all about numbers you can measure or count. Let's get started!


Types of Quantitative Variables

Before we jump into graphs, let's quickly review the types of quantitative variables:

  • Discrete Variables: These are countable. Think of things like the number of cars ๐Ÿš— in a parking lot or students in a class. You can list out the possible values.

  • Continuous Variables: These can take on infinitely many values within a range. Examples include height, time, or temperature. You can't count them because there's always a value between any two values. โ™พ๏ธ


Graphical Displays for Quantitative Data

Time to visualize! Here are the main displays you need to know:

Histograms

A histogram uses bars to show the distribution of your data. The data is grouped into 'bins,' and the height of each bar shows how many data points fall into that bin. No spaces between bars unless there is a gap in the data. The x-axis shows the data values, and the y-axis shows the frequencies. ๐Ÿ˜

Histogram Example

_Source: W3Schools_

Key Concept

Remember, histograms are for quantitative data. The bars touch unless there's a gap in your data. Always check the quantitative dat...

Question 1 of 12

Ready to roll? ๐Ÿ˜Ž Which of the following is an example of a discrete variable?

The height of a tree

The temperature of a room

The number of students in a class

The time it takes to run a mile