What is a Scatter Plot? Definition & Examples for Grade 8

📚 What is a Scatter Plot?

A scatter plot is a type of graph that uses points to display values for two different variables. It helps us see if there's any correlation, or relationship, between those variables.

• 📈 Variables: A scatter plot uses two variables, usually called x and y. The x-variable is plotted on the horizontal axis, and the y-variable is plotted on the vertical axis.
• 📍 Points: Each point on the scatter plot represents a single data point, showing the values of x and y for that data point.
• 📉 Correlation: By looking at the pattern of the points, we can determine if there's a relationship between the variables. If the points tend to move upwards together, it's a positive correlation. If they move downwards together, it's a negative correlation. If the points are scattered randomly, there's little to no correlation.
• ➕ Outliers: Sometimes, you might see points that are far away from the main cluster of points. These are called outliers, and they can sometimes skew the correlation.

Quick Study Guide

• 📊 Scatter plots show the relationship between two variables.
• 📈 Positive correlation: as one variable increases, the other increases.
• 📉 Negative correlation: as one variable increases, the other decreases.
• ↔️ No correlation: no clear relationship between variables.
• 🎯 Outliers: data points that are far away from the other points.

Practice Quiz

1. What type of graph uses points to display values for two different variables?
   1. A) Bar graph
   2. B) Line graph
   3. C) Scatter plot
   4. D) Pie chart
2. What does each point on a scatter plot represent?
   1. A) The average of all data
   2. B) A single data point showing the values of x and y
   3. C) The maximum value
   4. D) The minimum value
3. What is it called when the points on a scatter plot tend to move upwards together?
   1. A) Negative correlation
   2. B) Positive correlation
   3. C) No correlation
   4. D) Outlier
4. What is it called when the points on a scatter plot tend to move downwards together?
   1. A) Positive correlation
   2. B) No correlation
   3. C) Outlier
   4. D) Negative correlation
5. What do we call points that are far away from the main cluster of points?
   1. A) Average points
   2. B) Median points
   3. C) Outliers
   4. D) Cluster points
6. If the points on a scatter plot are scattered randomly, what does this indicate?
   1. A) A strong positive correlation
   2. B) A strong negative correlation
   3. C) Little to no correlation
   4. D) Perfect correlation
7. In a scatter plot showing the relationship between hours studied and test scores, if students who study more tend to get higher scores, what type of correlation is present?
   1. A) Negative correlation
   2. B) No correlation
   3. C) Positive correlation
   4. D) Inverse correlation