The Line of Best Fit Linear Regression. Definition - A Line of Best or a trend line is a straight line on a Scatter plot that comes closest to all of.

Slides:



Advertisements
Similar presentations
Exponential Regression
Advertisements

Section 10-3 Regression.
Scatter Diagrams and Linear Correlation
The Best-Fit Line Linear Regression. PGCC CHM 103 Sinex How do you determine the best-fit line through data points? x-variable y-variable Fortunately.
5-7: Scatter Plots & Lines of Best Fit. What is a scatter plot?  A graph in which two sets of data are plotted as ordered pairs  When looking at the.
S TATISTICS : U SING S CATTER P LOTS. V OCABULARY Bivariate Scatter Plot Positive Correlation Negative Correlation No Correlation.
S TATISTICS : U SING S CATTER P LOTS LINE OF BEST FIT.
Graphing Scatter Plots and Finding Trend lines
Unit 5, Lesson 11 Mrs. King. Press the STAT button Choose 1: Edit…
Scatter-plot, Best-Fit Line, and Correlation Coefficient.
5-7 Scatter Plots. _______________ plots are graphs that relate two different sets of data by displaying them as ordered pairs. Usually scatter plots.
How do I find the equation of a line of best fit for a scatter plot? How do I find and interpret the correlation coefficient, r?
Correlation Correlation measures the strength of the LINEAR relationship between 2 quantitative variables. Labeled as r Takes on the values -1 < r < 1.
Objective: I can write linear equations that model real world data.
2-5 Using Linear Models Make predictions by writing linear equations that model real-world data.
2-5: Using Linear Models Algebra 2 CP. Scatterplots & Correlation Scatterplot ◦ Relates two sets of data ◦ Plots the data as ordered pairs ◦ Used to tell.
Describe correlation EXAMPLE 1 Telephones Describe the correlation shown by each scatter plot.
10/18/2015 V. J. Motto 1 Chapter 1: Models V. J. Motto MAT 112 Short Course in Calculus Data Sets and the “STAT” Function.
Academy Algebra II 4.2: Building Linear Functions From Data HW: p (3-8 all,18 – by hand,20 – calc) Bring your graphing calculator to class on Monday.
Draw Scatter Plots and Best-Fitting Lines Section 2.6.
Scatter Diagrams Objective: Draw and interpret scatter diagrams. Distinguish between linear and nonlinear relations. Use a graphing utility to find the.
12/5/2015 V. J. Motto 1 Chapter 1: Linear Models V. J. Motto M110 Modeling with Elementary Functions 1.4 Linear Data Sets and “STAT”
CHAPTER curve fitting with linear functions.
Section 2.6 – Draw Scatter Plots and Best Fitting Lines A scatterplot is a graph of a set of data pairs (x, y). If y tends to increase as x increases,
5.7 Scatter Plots and Line of Best Fit I can write an equation of a line of best fit and use a line of best fit to make predictions.
Correlation The apparent relation between two variables.
Scatter Plots, Correlation and Linear Regression.
Scatterplots Chapter 7 Definition and components Describing Correlation Correlation vs. Association.
2.5 Using Linear Models A scatter plot is a graph that relates two sets of data by plotting the data as ordered pairs. You can use a scatter plot to determine.
Sec. 2-4: Using Linear Models. Scatter Plots 1.Dependent Variable: The variable whose value DEPENDS on another’s value. (y) 2.Independent Variable: The.
2.5 Using Linear Models P Scatter Plot: graph that relates 2 sets of data by plotting the ordered pairs. Correlation: strength of the relationship.
AP Statistics HW: p. 165 #42, 44, 45 Obj: to understand the meaning of r 2 and to use residual plots Do Now: On your calculator select: 2 ND ; 0; DIAGNOSTIC.
Scatterplots and Linear Regressions Unit 8. Warm – up!! As you walk in, please pick up your calculator and begin working on your warm – up! 1. Look at.
.  Relationship between two sets of data  The word Correlation is made of Co- (meaning "together"), and Relation  Correlation is Positive when the.
Mathematical Models A model is a mathematical representation of the relationship between two real-world quantities. After 2 hours of driving, Freddy finds.
Day 102 – Linear Regression Learning Targets: Students can represent data on a scatter plot, and describe how the variables are related and fit a linear.
Scatter Plot A scatter plot is a graph of a collection of ordered pairs (x,y). The ordered pairs are not connected The graph looks like a bunch of dots,
Regression and Median Fit Lines
6.7 Scatter Plots. 6.7 – Scatter Plots Goals / “I can…”  Write an equation for a trend line and use it to make predictions  Write the equation for a.
Linear Regression A step-by-step tutorial… Copyright © 2007 College of the Redwoods First edition by Aeron Ives.
Welcome to Algebra 2! Get out your homework Get out catalogs Get out writing utensils Put bags on the floor Be quiet!!! 3/2/ : Curve Fitting with.
Section 1.3 Scatter Plots and Correlation.  Graph a scatter plot and identify the data correlation.  Use a graphing calculator to find the correlation.
 This lesson covers two methods for finding an equation for a line that roughly models a set of data.  The first way is to eyeball a possible line,
UNIT 8 Regression and Correlation. Correlation Correlation describes the relationship between two variables. EX: How much you study verse how well you.
1.6 Modeling Real-World Data with Linear Functions Objectives Draw and analyze scatter plots. Write a predication equation and draw best-fit lines. Use.
Warm Up Practice 6-5 (p. 78) #13, 15, 16, 18, 22, 25, 26, 27, 31 – 36
2.5 Scatter Plots & Lines of Regression
Module 15-2 Objectives Determine a line of best fit for a set of linear data. Determine and interpret the correlation coefficient.
5.7 Scatter Plots and Line of Best Fit
Exercise 4 Find the value of k such that the line passing through the points (−4, 2k) and (k, −5) has slope −1.
2.5 Scatterplots and Lines of Regression
Journal Heidi asked 4 people their height and shoe size. Below are the results. 63 inches inches inches inches 8 She concluded that.
Lesson 5.3 How do you write linear equations in point-slope form?
Correlation and Regression
Warm Up Please sit down and clear your desk. Do not talk. You will have until lunch to finish your quiz.
4.5 Analyzing Lines of Fit.
Scatter Plots and Line of Best Fit
Equations of Lines and Modeling
Scatter Plots and Best-Fit Lines
Drill #23* Find the equation of (in point- slope form) and graph the following linear functions: 1. Passing through the points (-1, -1) and (1, 3) 2.
Line of best fit.
Line of Best Fit.
DRILL Given each table write an equation to find “y” in terms of x.
Linear Correlation and Regression
y = mx + b Linear Regression line of best fit REMEMBER:
Objective: Interpret Scatterplots & Use them to Make Predictions.
SECTION 6.2 Linear Regression
Linear Models We will determine and use linear models, and use correlation coefficients.
LEARNING GOALS FOR LESSON 2.7
Scatter Plots That was easy Year # of Applications
Presentation transcript:

The Line of Best Fit Linear Regression

Definition - A Line of Best or a trend line is a straight line on a Scatter plot that comes closest to all of the dots on the graph. A Line of Best Fit may pass through some or the points, none of the points or all of the points. You can find the line of best fit by hand (paper and pencil) or with your graphing calculator.

A Line of Best Fit is useful because it allows us to: –Understand the type and strength of the relationship between two sets of data –Predict missing Y values for given X values, or missing X values for given Y values

How do you determine the best-fit line through data points? x-variable y-variable Fortunately technology, such as the graphing calculator and Excel, can do a better job than your eye and a ruler!

Line of Best Fit by Hand Create your scatter plot of the data provided. Using a ruler (upright), position it so that the plotted points are as close to the ruler as possible. Draw the line of best fit Find 2 points that you think would be on your best fit line. Find the slope of the 2 points. Plug the slope and one point into point slope formula y-y 1 =m(x-x 1 ) to find the equation of the line. Put the equation in slope intercept form (solve for y)

Line of Best Fit on Calculator 1. Enter the data in the calculator lists. Place the data in L 1 and L 2. STAT, #1Edit, type values into the lists 2. Prepare a scatter plot of the data. Set up for the scatterplot. 2 nd StatPlot - choose the first icon – choices shown at right. Choose ZOOM #9 ZoomStat.

Graph will look something like this. 3. Have the calculator determine the line of best fit. STAT → CALC #4 LinReg(ax+b) Include the parameters L 1, L 2, Y 1. (Y 1 comes from VARS → YVARS, #Function, Y 1 )

Graph will look something like this. 3. Have the calculator determine the line of best fit. STAT → CALC #4 LinReg(ax+b) Include the parameters L 1, L 2, Y 1. (Y 1 comes from VARS → YVARS, #Function, Y 1 )

You now have the values of a and b needed to write the equation of the actual line of best fit. Example: See values right and substitute for a and b y = 11.73x (2 decimals) 4. Graph the line of best fit. Simply hit GRAPH.

Correlation Coefficient r r tells you how strong the relationship between the 2 variables is and how dependable the equation is. r is between -1 and 1. The closest it is to 0, the weaker the correlation. The closer it is to 1 or -1, the stronger the correlation