chapter four day two
Download
Skip this Video
Download Presentation
Chapter Four Day Two

Loading in 2 Seconds...

play fullscreen
1 / 17

Chapter Four Day Two - PowerPoint PPT Presentation


  • 118 Views
  • Uploaded on

Chapter Four Day Two. Power Models. Homework. P. 285 11,12,13. Review of Exponential Models. Show that if y = a*b x taking then there is a linear relationship between x and log(y). Review of Exponential Models. Make scatterplot and note very strong non-linear form.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' Chapter Four Day Two' - magda


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
homework
Homework
  • P. 285 11,12,13
review of exponential models
Review of Exponential Models
  • Show that if y = a*bx taking then there is a linear relationship between x and log(y).
review of exponential models1
Review of Exponential Models
  • Make scatterplot and note very strong non-linear form.
  • Take the log of the y-values and put the results in L3.
  • Do a linreg on L1 vs. L3
  • Write log(y) = bx + a
  • Untransform to get final exponential model
example
Example
  • Untransform log(y) = ax + b
power models y a x b
Power Models y = a* xb
  • Hierarchy of Powers
  • y = ax linear
  • Y = ax2 quadratic
  • Y = ax3 cubic
  • Y = ax4 quadratic
  • Y = ax5 5th degree
  • For large x axb < abx for any b
example1
Example
  • Show that if y = abx then there is a linear relationship between log x and log y.
example2
Example
  • Untransform log y = alog(x) + b
steps to making a power model
Steps to Making a Power Model
  • Plot data and note nonlinear form
  • Put log of the x-values in L3
  • Put log of y –values in L4
  • Do linreg on log x vs log y
  • Write log(y) = a(log x) +b
  • Untransform to get final power model
example planets
Example - Planets
  • Find a model that predicts a planet’s period of revolution using the distance from the sun as an explanatory variable.
untransform linear log log model to get final power model
Untransform linear log-log Model to get final power model
  • ln(period) = .000254 + 1.50 ln(distance)
evaluating a model
Evaluating a Model
  • Comment on r2
  • Comment on residual Plot
ad