## Making Predictions With Scatter Plots in the Real World

This Real World 3 Act Math Task will have students **making predictions** via **interpolation** and **extrapolation** using **scatter plots** and a **line of best fit**.

## Related Math Topics:

Data management of two-variables including:

- making predictions between two-variables,
- creating scatter plots,
- classifying correlations as positive/negative and strong/weak, and
- interpolating and extrapolating using a line of best fit.

This task can be extended to linear relationship and equations by having students determine the equation of a line for the line of best fit to make predictions.

## Act 1: Lighting the Candle

Students will watch act 1 and make interpolations and extrapolations related to how long it will take for the candle to burn to ____ cm tall or to completely burn out.

## Act 2: Students Request Information

At this stage, students may be requesting more information, such as:

- how long was the candle before it was lit?
- how long did it take to get to half the size?

Here are some images that can also help when gradually releasing more information to your students:

## Act 3: Compare Student Predictions to Reality

## Sequel / Extensions

**What if…**

…we had a 26 cm candle with the same diameter as the last candle? How long would it take to burn out?

… the relationship between

height of the candleandtimewas perfectly linear? (a perfectly straight line). Whatcouldthe table of values and graph look like?

This 3 act math task can easily be extended to different situations including a larger/smaller candle, thicker candles and many other ideas that I’m sure you’ll think up as you prepare to use this task.

## Resources:

## Sequel #2:

Added Monday April 14th, 2014

This activity is a great one to address the **Understanding Characteristics of Linear Relations** specific expectation from MPM1D – Principles of Mathematics, 9:

LR2.04 – determine the equation of a line of best fit for a scatter plot, using an informal process (e.g., using a movable line in dynamic statistical software; using a process of trial and error on a graphing calculator; determining the equation of the line joining two carefully chosen points on the scatter plot).

Click below to grab a math handout that has some of the given information and some area for students to work:

Please comment to let me know how it worked in your classroom!

Nice task Kyle, I especially like the use of a scatterplot! Not too many tasks that do this! Planning on using this with grade 9 applied when we get to scatterplots.

Thanks for the feedback, Jon. I’m going to try it tomorrow with my applied class and see if we can start talking equations a bit. We will see how it goes!

Cheers!