The Least-Squares Line Introduction

Slides:



Advertisements
Similar presentations
Chapter 3 Examining Relationships Lindsey Van Cleave AP Statistics September 24, 2006.
Advertisements

AP Statistics Section 3.2 C Coefficient of Determination
Psy302 Quantitative Methods
6-1 Introduction To Empirical Models 6-1 Introduction To Empirical Models.
Statistical Relationship Between Quantitative Variables
1 Relationships We have examined how to measure relationships between two categorical variables (chi-square) one categorical variable and one measurement.
Linear Regression Analysis
Correlation & Regression
Chapter 4 Two-Variables Analysis 09/19-20/2013. Outline  Issue: How to identify the linear relationship between two variables?  Relationship: Scatter.
Linear Regression and Correlation
Relationship of two variables
Managerial Economics Demand Estimation. Scatter Diagram Regression Analysis.
Linear Regression Least Squares Method: the Meaning of r 2.
Section 5.2: Linear Regression: Fitting a Line to Bivariate Data.
Regression Regression relationship = trend + scatter
Correlation and Regression Basic Concepts. An Example We can hypothesize that the value of a house increases as its size increases. Said differently,
Psy302 Quantitative Methods
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.
John C. Mayer Introduction to Mathematical Modeling 1 Curve Fitting.
Linear Prediction Correlation can be used to make predictions – Values on X can be used to predict values on Y – Stronger relationships between X and Y.
Regression Analysis. 1. To comprehend the nature of correlation analysis. 2. To understand bivariate regression analysis. 3. To become aware of the coefficient.
Psychology 202a Advanced Psychological Statistics October 22, 2015.
1 Simple Linear Regression and Correlation Least Squares Method The Model Estimating the Coefficients EXAMPLE 1: USED CAR SALES.
Chapter 8 Linear Regression. Fat Versus Protein: An Example 30 items on the Burger King menu:
Simple Linear Regression The Coefficients of Correlation and Determination Two Quantitative Variables x variable – independent variable or explanatory.
Method 3: Least squares regression. Another method for finding the equation of a straight line which is fitted to data is known as the method of least-squares.
Chapter 14 Introduction to Regression Analysis. Objectives Regression Analysis Uses of Regression Analysis Method of Least Squares Difference between.
Correlation and Regression Basic Concepts. An Example We can hypothesize that the value of a house increases as its size increases. Said differently,
Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education.
Describing Bivariate Relationships. Bivariate Relationships When exploring/describing a bivariate (x,y) relationship: Determine the Explanatory and Response.
Linear Regression Essentials Line Basics y = mx + b vs. Definitions
Chapter 8 Linear Regression.
Topic 13: Quantitative-Quantitative Association Part 1:
Linear Regression.
CHAPTER 3 Describing Relationships
CHAPTER 3 Describing Relationships
Regression Chapter 6 I Introduction to Regression
3.1 Examples of Demand Functions
SIMPLE LINEAR REGRESSION MODEL
Multiple Regression.
Linear Regression Prof. Andy Field.
Chapter 3: Linear models
Describing Bivariate Relationships
Linear Regression.
Regression Models - Introduction
EQ: How well does the line fit the data?
CHAPTER 3 Describing Relationships
Linear regression Fitting a straight line to observations.
Investigation 4 Students will be able to identify correlations in data and calculate and interpret standard deviation.
Least Squares Method: the Meaning of r2
BA 275 Quantitative Business Methods
Determine the type of correlation between the variables.
Chapter 7 Demand Forecasting in a Supply Chain
11C Line of Best Fit By Eye, 11D Linear Regression
CHAPTER 3 Describing Relationships
CHAPTER 3 Describing Relationships
Ch 4.1 & 4.2 Two dimensions concept
CHAPTER 3 Describing Relationships
Lesson – How can I measure my linear fit? - Correlations
CHAPTER 3 Describing Relationships
CHAPTER 3 Describing Relationships
Algebra Review The equation of a straight line y = mx + b
A medical researcher wishes to determine how the dosage (in mg) of a drug affects the heart rate of the patient. Find the correlation coefficient & interpret.
Chapter 3 Vocabulary Linear Regression.
Correlation & Trend Lines
Statistics 101 CORRELATION Section 3.2.
Regression and Correlation of Data
Solution to Problem 2.25 DS-203 Fall 2007.
CHAPTER 3 Describing Relationships
Presentation transcript:

The Least-Squares Line Introduction

Many lines appear to fit the data well. Source: http://www.studyworksonline.com, 8/13/03

Many lines appear to fit the data well. Source: http://www.studyworksonline.com, 8/13/03

Many lines appear to fit the data well. Source: http://www.studyworksonline.com, 8/13/03

Many lines appear to fit the data well. Source: http://www.studyworksonline.com, 8/13/03

Many lines appear to fit the data well. Source: http://www.studyworksonline.com, 8/13/03

Many lines appear to fit the data well. There is one line that is often said to fit the best (especially when there are no outliers) The Least Squares Line Error2 Source: http://www.studyworksonline.com, 8/13/03 Actual Actual – Predicted = Error Predicted

Source: http://www.studyworksonline.com, 8/13/03

Least-Squares Line The Least Squares Line is the line that minimizes the sum of the squares of the errors. Source: http://www.studyworksonline.com, 8/13/03

Least-Squares Line We have qualitative ways of expressing how appropriate the linear model is like “a very appropriate model”, or “ a fairly appropriate model”, or “ an inappropriate model”. There is also a quantitative way to express the “goodness of fit” called the correlation coefficient, r. The correlation coefficient, r, measures the strength of the linear relationship between the two variables.

The Least-Squares Line Introduction