Graphing and Interpreting Scatter Plots Objective To graph

Graphing and Interpreting Scatter Plots Objective - To graph and interpret scatter plots.

Scatter Plot • A scatter plot is a graph of a collection of ordered pairs (x, y). • X –independent/horizontal axis • Y- dependent/vertical axis • The graph looks like a bunch of dots, but some of the graphs are a general shape or move in a general direction.

Positive Correlation Review • X-coordinates and the ycoordinates both increase, then it is POSITIVE CORRELATION.

Real Life Positive Correlation • If you look at the age of a child and the child’s height, you will find that as the child gets older, the child gets taller. Because both are going up, it is positive correlation. Age 1 2 3 Height 4 5 6 7 8 25 31 34 36 40 41 47 55 Justification 1. Trend is increasing. 2. Correlation: Positive 3. When the age increase the height

Negative Correlation • X-coordinates and the Ycoordinates have one increasing and one decreasing, then it is NEGATIVE CORRELATION.

Real Life Negative Correlation • If you look at the age of your family’s car and its value, you will find as the car gets older, the car is worth less. This is negative correlation. Age 1 2 3 4 5 of car Value $30, 000 $27, 000 $23, 500 $18, 700 $15, 350 Justification 1. Trend is decreasing. 2. Correlation: negative 3. When the age of car increase the value decreases

No Correlation • no pattern • scattered • This means the two are not related.

No Correlation • Size shoe a baseball player wears and their batting average • Not related because the shoe size does not make the player better or worse, then are not related.

Interpreting Scatter Plots

Linear trend or not a trend a) c) Negative Correlation e) Positive Correlation b) d) f) Constant Correlation

I DO: Model and Guided Practice y Sport Utility Vehicles (SUVs) Sales in U. S. 1991 1992 1993 1994 1995 0. 9 1. 1 1. 4 1. 6 1. 7 Justification 1. Trend is ______ 2. Correlation: 3. Vehicle Sales (Millions) Year Sales (in Millions) 5 4 3 2 1 x Year

Insert Lesson Title Here We Do: Guided Practice 1. Use the given information to make a scatter plot. Make sure to include Name for Graph, label each axes, and have appropriate intervals. Grading Period 1 2 3 Number of A’s 5 6 8 10 Justification 1. Trend is _______. 2. Correlation: _______ 3. 4

Partner Activity: Plot the data on the graph such that homework time is on the y-axis and TV time is on the x-axis. Time Spent Student Watching TV on Homework Sam 30 min. 180 min. Jon 45 min. 150 min. Lara 120 min. 90 min. Darren 240 min. 30 min. Megan 90 min. Pia 150 min. 90 min. Crystal 180 min. 90 min.

Plot the data on the graph such that homework time is on the y-axis and TV time is on the x-axis. TV Homework 240 45 min. 150 min. 120 min. 90 min. 240 min. 30 min. 90 min. 120 min. 150 min. 120 min. 180 min. 90 min. Time on Homework 30 min. 180 min. 210 180 150 120 90 60 30 30 90 150 210 60 120 180 240 Time Watching TV

Describe the relationship between time spent on homework and time spent watching TV. 240 Trend is decreasing. 210 180 Time on Homework Trend appears linear. Negative correlation. 150 120 90 60 30 30 90 150 210 60 120 180 240 Time Watching TV

You Do Independent Work

Closure • Fist of 5 • Wrap Up