Scatter Plots
A Scatter (XY) Plot has points that show the relationship between two sets of data.
In this example, each dot shows one person's weight versus their height.
Example:
The local ice cream shop keeps track of how much ice cream they sell versus the noon temperature on that day. Here are their figures for the last 12 days:
| Ice Cream Sales vs Temperature | |
| Temperature °C | Ice Cream Sales |
|---|---|
| 14.2° | $215 |
| 16.4° | $325 |
| 11.9° | $185 |
| 15.2° | $332 |
| 18.5° | $406 |
| 22.1° | $522 |
| 19.4° | $412 |
| 25.1° | $614 |
| 23.4° | $544 |
| 18.1° | $421 |
| 22.6° | $445 |
| 17.2° | $408 |
And here is the same data as a Scatter Plot:
It is now easy to see that warmer weather leads to more sales, but the relationship is not perfect.
Line of Best Fit
We can also draw a "Line of Best Fit" (also called a "Trend Line") on our scatter plot:
Try to have the line as close as possible to all points, and as many points above the line as below.
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