Download presentation

Presentation is loading. Please wait.

Published byIrene Rumbley Modified over 3 years ago

1
AP Statistics Section 15 B

2
Estimating the Parameters To estimate the true regression line, we will use the calculated least-squares regression line. The y-intercept, a, will be an unbiased estimator of the true y- intercept,, and the slope, b, is an unbiased estimator of the true slope,.

3
The remaining parameter of the model is the standard deviation,, which describes the variability of the response y about the true regression line. We will estimate the unknown standard deviation by a sample standard deviation of the residuals (i.e. the standard error about the least-squares line)

4
The slope,, of the true regression line is usually the most important parameter in a regression problem. The confidence interval for has the familiar form: estimate. Because b is our estimate, the confidence interval becomes __________. In this expression, the standard error of the least-squares slope b is and t* is the critical value for the t(n – 2) density curve with area C between –t* and t*.

5
Example: Construct and interpret a 95% confidence interval for the slope of the true regression line for the crying baby/IQ scenario.. 95. 025

6
The figure below shows the basic output for the crying study from the regression command in the Minitab software package. Regression Analysis The regression equation is IQ = 91.3 + 1.49 Crycount PredictorCoefStDevTP Constant91.2688.93410.220.000 Crycount1.49290.48703.070.004 S = 17.50

Similar presentations

OK

© 2010 Pearson Prentice Hall. All rights reserved Least Squares Regression Models.

© 2010 Pearson Prentice Hall. All rights reserved Least Squares Regression Models.

© 2017 SlidePlayer.com Inc.

All rights reserved.

Ads by Google

Ppt on information technology act 2008 Ppt on flash animation tutorial Ppt on plasma arc welding Convert doc file to ppt online Ppt on endangered species of birds Ppt on image demosaicing Ppt on product advertising samples Converter pub to ppt online training Ppt on brushless servo motor Animated ppt on human digestive system