# Scatter Plots

### Correlations and Line of Best Fit

## Instructions

Follow the directions provided before each task. As needed, each task should be completed on a separate sheet of paper. Your work should be shown neatly. These tasks will be a cumulative grade, but you will also be assessed on how neat your assignments are.

As we move through the week and you are working on the tasks, you may ask questions for assistance as you need it. We will work through some of the problems together as a whole class as well.

## Scatter Plots Reference Guide

At the bottom of the notes website are 12 questions. Try to answer all the questions.

## Types of Correlations

## Positive Correlation As the independent variable (x) increases, the dependent variable (y) increases. Ex: Amount of time spent studying for a math test vs. test grade. | ## Negative Correlation As the independent variable (x) increases, the dependent variable (y) decreases. Ex: Distance driven vs. tire tread. | ## No CorrelationThe data points are unrelated. There is no relation between the independent (x) and dependent (y) variables. Ex: The height of a student vs. the student's grades. |

## Positive Correlation

Ex: Amount of time spent studying for a math test vs. test grade.

## Negative Correlation

Ex: Distance driven vs. tire tread.

## Task 1: Practice Identifying Correlation

## Task 2: Practice Constructing Scatter Plots

## Line of Best Fit

## Drawing Line of Best Fit

## Calculating Line of Best Fit

Ex: (9,9) (1,5)

Slope: y-y/x-x

9-5/9-1 = 4/8 = 1/2

y = mx + b

5 = 1/2(1) + b

5 = 1/2 + b

9/2 = b

Line of Best Fit: y = 1/2x + 9/2

## Task 3: Line of Best Fit Practice

## Interpolation & Extrapolation

## Practice Worksheets

## Task 4: Practice Worksheet #1

Worksheet can be found at:

## Task 4: Practice Worksheet #2

## Create Your Own Scatter Plots

Use the information in the pictures below to create scatter plots on the website. Then use the information in the scatter plot to answer any questions that follow.