Scatter Plots in Science

GED Science test includes question with a scatter plot.

This lesson is a part of Onsego GED Prep.

Video Transcription

In this lesson, we will talk about a different type of graph that you often see on the GED science test: the scatter plot.

A scatter plot is a type of graph that does not connect the points with lines.

Unlike other graphs that show continuous events, scatter plots are used to show correlations and associations, or the lack thereof, between two variables.

Let’s take a look at how it works.

The scatter plot “Tree Age vs. Height” shows the relationship between the age of trees and their height.

What is a valid conclusion based on this scatter plot?

A. Older trees have shorter heights.

B. Trees’ height and age are not correlated.

C. As trees get older, they tend to grow taller.

D. All trees grow at the same rate regardless of age.

The Correct Answer is option C. As trees get older, they tend to grow taller.

Explanation: By examining the scatter plot, you can see that as the age of the trees increases (plotted on the x-axis), the height of the trees (plotted on the y-axis) also increases. To helps us to see it we draw a temporary line, it helps us to see the trends.

This indicates a positive correlation between tree age and height, meaning that as trees get older, they tend to grow taller.

Now let’s look at another scatter plot.
This time, we’ll examine whether there’s a relationship between the amount of water plants receive and their growth.

What is a valid conclusion based on this scatter plot?

Is it A: More water always results in more plant growth?

B: Water amount and plant growth are directly correlated?

C: Water amount and plant growth do not show a clear correlation?

or D: Less water results in more plant growth?

The Correct Answer is C. Water amount and plant growth do not show a clear correlation.

Explanation: By examining the scatter plot, you can see that there is no consistent pattern where an increase in water amount leads to more plant growth or vice versa. The data points are scattered without forming a clear trend, indicating that water amount and plant growth are not strongly correlated in this case.

Let’s check another a bit more challenging example:

Scientists are studying the accumulation of impact craters on Mars to understand the planet’s geological history. Various sites have been analyzed using radiometric dating methods. The data below shows the age of the sampled regions and the corresponding crater density measured. By analyzing these data, researchers can estimate the ages of different Martian surface areas based on their crater densities.

Based on the graph, which conclusion can be drawn about the relationship between the age of Martian surfaces and crater density?

Options
A. Older Martian surfaces have a lower density of large craters.
B. Younger Martian surfaces have a higher density of large craters.
C. There is no clear relationship between the age of Martian surfaces and crater density.
D. Older Martian surfaces have a higher density of large craters.

This question might seem complex at first glance, and you might think it impossible to answer without a deep understanding of radiometric dating methods. However, I will show you how we can infer the correct answer simply by analyzing the scatter plot.

Let’s dive into the graph:

The horizontal axis, or X-axis, represents the ‘Age of Sample (billions of years)’, indicating how old the Martian surface is. The vertical axis, or Y-axis, measures the ‘Density of Large Craters (Number per square km)’, showing how many large craters are found per square kilometer.
Observing the Trend: Notice how the points are arranged. The scatter plot reveals a descending trend from left to right, suggesting that as the age of the sample decreases, the density of large craters also decreases.
Interpreting the Data: The highest density of craters correlates with the oldest samples. For instance, a 4 billion-year-old sample shows a crater density of almost 0.03 per square kilometer. Conversely, the youngest samples, such as the 0.2 billion-year-old surface, have the lowest crater density, approaching 0.
Therefore, this answer is correct: older Martian surfaces show a higher density of large craters. This example perfectly illustrates how scatter plots can be used to answer questions about complex scientific issues.

Last Updated on October 20, 2025.