what is the difference between a scatter plot and a line graph?
http://mste.illinois.edu/courses/ci330ms/youtsey/scatterinfo.html
http://www.ncsu.edu/labwrite/res/gh/gh-linegraph.html
A scatter plot and a line graph are both used to visualize relationships between variables, but they have some key differences in terms of how the data is represented.
1. Data Representation:
- Scatter Plot: In a scatter plot, each data point is represented individually as a dot or marker. The x-axis represents one variable, the y-axis represents another variable, and each dot on the plot represents the corresponding values of the variables.
- Line Graph: In a line graph, the data points are connected with straight lines to show the trend or pattern over time or across sequential variables. Each data point is represented as a point on the line, and the x-axis typically represents time or another sequential variable.
2. Purpose:
- Scatter Plot: Scatter plots are commonly used to show the relationship between two continuous variables. They help identify patterns, trends, clusters, or outliers in the data and determine if there is a correlation between the variables.
- Line Graph: Line graphs are used to show the trend or change in data over time or across sequential variables. They are particularly useful for illustrating time-series data, such as tracking stock prices, temperature changes, or population growth.
3. Interpretation:
- Scatter Plot: By examining the dispersion of the data points on a scatter plot, you can make observations about the relationship between the variables. If the points are closely clustered together, it suggests a strong correlation, whereas a scattered pattern indicates a weaker or no correlation.
- Line Graph: In a line graph, the slope and direction of the line represent the trend or change over time or across sequential variables. A steep upward slope indicates a positive trend, while a steep downward slope represents a negative trend. A flat line suggests no change.
To create a scatter plot or line graph, you can use various software or even perform it manually by plotting the data points on a graphing paper or by using spreadsheet software like Microsoft Excel or Google Sheets. These programs have built-in functions to generate scatter plots and line graphs based on your data.