Yours

3.16: Scatterplots (3 of 5)

Concepts in Statistics · LibreTexts

0%

Contents

    Text

    Size
    100%
    Theme
    Typeface
    Line length
    Spacing

    From LibreTexts, under CC BY 4.0, as the source states it; its equations are written in TeX, which the PDF shows typeset. This page at LibreTexts.

    Learning Objectives

    • Use a scatterplot to display the relationship between two quantitative variables. Describe the overall pattern (form, direction, and strength) and striking deviations from the pattern.

    Now we return to our previous example. We apply the ideas of direction, form, and strength to describe the relationship between the age of the driver and the maximum distance to read a highway sign. Here is the scatterplot:

    Scatterplot showing negative direction: Increased age is associated with decreased reading distance.

    Direction: The direction of the relationship is negative. An increase in age is associated with a decrease in reading distance, which makes sense because older drivers tend to have diminished eyesight. So most older drivers can read the sign only when they are close to it. In other words, they have a shorter maximum reading distance.

    Scatterplot showing linear form in relation of driver age to reading distance

    Form: The form of the relationship is linear.

    Strength: The data points are fairly close to the line, so the relationship is moderately strong. Do not worry if you feel uncertain about describing the strength of a relationship. We mentioned earlier that descriptions of strength are not very precise. We develop a more precise measure of the strength shortly.

    Outliers: There are no outliers. All the data points tend to follow the linear pattern.

    Contributors and Attributions

    CC licensed content, Shared previously

    This page titled 3.16: Scatterplots (3 of 5) was last modified on Mon, 07 Dec 2020 07:04:02 GMT and is shared under a CC BY 4.0 license and was authored, remixed, and/or curated by Lumen Learning.