Download presentation
Presentation is loading. Please wait.
1
Business 205
2
Review Chi-Square
3
Preview Regression
4
Linear Equations Straight line representation of an equation General formula Y = bX + a b is a constant (slope) a is a constant (Y-intercept)
5
Regression Finding the best-fitting straight line for a set of data Regression line The resulting straight line
6
Least-Squares Solution Best-fitting regression line will have the least squared error Best fitting line for the scatterplot data
7
Least-Squares Solution
8
Regression Equation Example You have the following data points in X and Y (X, Y) format and want to know the best fitting line for your data. Find the mean for each set of scores: M x = 5 M y = 6 XY 711 43 65 34 57
9
Regression Equation Example XYX - M x Y - M Y (X - M x )(Y - M Y )(X - M x ) 2 7117 – 5 = 211 – 6 = 52*5 = 10 (2) 2 = 4 434 – 5 = -13 – 6 = -3-1*-3 = 3 (-1) 2 = 1 656 – 5 = 15 – 6 = -11*-1 = -1 (1) 2 = 1 343 – 5 = -24 – 6 = -2-2*-2 = 4 (-2) 2 = 4 575 – 5 = 07 – 6 = 10*1 = 0 (0) 2 = 0 Sum of Product = 16 SS x = 10
10
Regression Equation Example
11
Plotting the Regression Line XY 711 43 65 34 57
12
Excel Regression Linest(y values, x values) Highlight 2 cells Type in the equation Ctrl+Shift+Enter 2 numbers appear Slope, y-intercept Intercept(y values, x values) Slope(y values, x values)
Similar presentations
© 2024 SlidePlayer.com. Inc.
All rights reserved.