--- title: "Scatter Graphs" description: "Plot bivariate data on a scatter graph with correctly labelled axes and appropriate scales; describe the correlation (positive, negative, none) and draw an estimated line of best fit where appropriate" canonical: https://lightmysky.com/learn/mathematics/scatter-graphs-mt_BdAeZJUOir source: https://lightmysky.com/learn/mathematics/scatter-graphs-mt_BdAeZJUOir.md retrieved: 2026-10-19 --- > **Agent view.** This is the Markdown twin of the page, for tools and assistants. > When to use this site, and the call that answers each job: https://lightmysky.com/agent-instructions.md > API description (OpenAPI 3.1): https://lightmysky.com/openapi.json · Authentication: https://lightmysky.com/auth.md > Pricing: https://lightmysky.com/pricing.md · Catalog: https://lightmysky.com/llms.txt · Full catalog: https://lightmysky.com/llms-full.txt > Every machine-readable file on this domain: https://lightmysky.com/.well-known/ai-catalog.json > Ask for Markdown with `Accept: text/markdown`, a `.md` address, or `?mode=agent`. # Scatter Graphs Plot bivariate data on a scatter graph with correctly labelled axes and appropriate scales; describe the correlation (positive, negative, none) and draw an estimated line of best fit where appropriate Subject: Mathematics · Area: Data & Statistics · Ages 13 to 14 Page: https://lightmysky.com/learn/mathematics/scatter-graphs-mt_BdAeZJUOir ## Ready when they can - Plot 10 data points on a scatter graph with correct axis labels and a consistent scale - Draw a line of best fit by eye, ensuring roughly equal numbers of points above and below - Use the line of best fit to estimate a y-value for a given x-value within the data range ## Lesson: Lines of Best Fit on Scatter Graphs A scatter graph shows how two things about the same item are related, like hours of sleep and test scores for a group of students. Each point stands for one item, plotted using its two values as coordinates. Before you plot anything, label both axes clearly and choose a scale where equal gaps mean equal amounts, all the way along. **Example.** Say you're comparing hours of sleep with test scores for 10 students. One student slept 5 hours and scored 60. You'd find 5 on the sleep axis, go up until you reach 60 on the score axis, and mark a single point there. Do that for all 10 students and you get 10 points spread across the graph. Once your points are plotted, you can draw a line of best fit. It's a single straight line drawn through the middle of the points, showing the overall trend rather than joining any two points exactly. Aim for roughly the same number of points above the line as below it. *(drawing: A good line of best fit balances the points: about the same number above it as below it.)* To estimate a value with your line, find your known value on one axis, trace up or across to the line, then read off the other axis. This only works for values inside the range you actually plotted; going beyond that range is just a guess. **Recap.** Label your axes with an even scale, draw one straight line of best fit balanced through the points, then use it to estimate values only within your data's range. ## Practice 20 questions on this page, each with its working shown.