October 15 – 30, 2015
Scatterplots & Correlation – Part I DAY 1
(Oct. 12-13)
The following video (13min32sec) https://www.youtube.com/watch?v=iLrhCsVAXCY covers the following concepts and skills to master from the chapter syllabus:
1. Defines the explanatory and response variables
2. Uses various sketches of scatterplots to model relationships between two quantitative variables
3. Tells how to interpret a scatterplot using the mandatory descriptors: direction, form, strength, and a summary statement of the relationship among the variables in context
4. Highlights the basic properties of correlation
Scatterplots & Correlation – Part II
There are two videos below for Part II. The first video covers the following concepts and skills to master from the chapter syllabus:
1. Demonstrates how to identify outliers in a scatterplot
2. Shows how to calculate and interpret correlation
3. Discusses how the correlation is influenced by outliers
Before, viewing the first video that is associated with Part II of Day 1, read the content located on this webpage: http://stattrek.com/statistics/correlation.aspx?Tutorial=AP
NOTE: When reading the content on this page, do not be overwhelmed by the formulas used to compute correlation. You can find the formula that will be given to you during the AP Exam on p. 152 of your textbook.
Once you have completed reading, view the video by clicking on the link () located near the top left of the webpage. (17min07sec)
Outliers affect correlation. Compare the scatterplot to the left below with the one to the right of it. The single outlier in the second plot greatly reduces the correlation - from 1.00 to 0.71.
Also, watch the second video below (3min21sec):
How Do Outliers Affect Correlation? https://www.youtube.com/watch?v=9UIcSlIciJI
Day 1 Continued…
How to graph scatterplots & find the correlation using the graphing calculator:
https://www.youtube.com/watch?v=zvH7ZMyTwWc
NOTE: In order to find the correlation: you must have your diagnostic on. In the video, STAT-CALC-option number 4 LinReg is used when computing r. We will use option 8 LinReg. Unlike Algebra, the intercept is typically written first in statistics – and then the slope when writing the equation of a line.
For Chapter 3 Project information – see wiki – Chapter 3 section
http://devans.cmswiki.wikispaces.net/AP+Stats+-+SEMESTER+1
Least Squares Regression – Part I DAY 2
(Oct. 14-15)
The following video https://www.youtube.com/watch?v=be2qEgDmaWc
(13min22sec) covers the following concepts and skills to master from the chapter syllabus:
1. Identify the slope and y intercept of a least squares regression line
2. Use the least squares regression line to predict y (y hat) for a given x
3. Explain the dangers of extrapolation
4. Calculate and interpret the residuals in context
5. Use coefficient of determination, r2 to assess how well the line fits the data
This short video (3min 27sec) shows how to use your calculator to get the LSRL and r
https://www.youtube.com/watch?v=sVeNrDLhgnI
The following video (8min 26sec) https://www.youtube.com/watch?v=JvS2triCgOY covers the following concept and skill from the chapter syllabus:
1. Calculate the equation for the least squares regression line (using the equation in your textbook)
The following video (13min44sec) https://www.youtube.com/watch?v=WHIi7Vc21cs covers the following concepts and skills to master from the chapter syllabus:
1. Find the slope and intercept of the least squares regression line from the means and standard deviations of x and y and their correlation.
2. Interpret the slope and y intercept of a least squares regression line in context
3. Use the least squares regression line to predict y (y hat) for a given x
4. Explain the dangers of extrapolation
For handouts given in class on Day 2 – see wiki
Extra Video (13min) – AP Stats: The LSRL https://www.youtube.com/watch?v=kKNzoPht_1I
Least Squares Regression – Part II DAY 3
(Oct. 16 & 19)
The following video (14min22sec) https://www.youtube.com/watch?v=w-fbn1Z5Lx4 covers the following concepts and skills to master from the chapter syllabus:
- NOTE: This video also helps you practice the calculator keystrokes when finding the LSRL
1. Calculate the equation for the least squares regression line
2. Interpret the slope and y intercept of a leas squares regression line
3. Calculate residuals
4. Construct and interpret residual plots to assess if a linear model is appropriate
The following video (22:59) https://www.youtube.com/watch?v=S9SbLiIGj04 covers the following concepts and skills to master from the chapter syllabus: *
1. Calculate and interpret residuals in context
2. Construct and interpret residual plots to assess if a linear model is appropriate for making predictions
3. Use r2 to determine how well the line fits the data
4. Calculate and interpret r2 in context of the problem
The following concepts and skills to master from the chapter syllabus should be noted in your textbook. Please read the following pages to assist you with understanding.
1. Use the standard deviation of the residuals to assess how well the line fits the data - p. 177
2. Interpret the standard deviation of the residuals in context – p. 177
3. Identify the equation of a least squares regression line from computer output – pp.182-183
4. Outliers and influential points in regression – p. 187
5. Explain why association doesn’t imply causation – p. 188
Least Squares Regression Day 4
(Oct. 20-21)
Complete Anscombe’s Data Activity – p.184 of book
QUIZ today – You will have to make it up upon return.
Chapter 3 Projects Due!!! Day 5
(Oct. 22 & 26)
Agenda: Project Presentations & Test Review
Day 6
TEST (Oct. 27-28)
Day 1
BEGIN CHAPTER 4 (optional) (Oct. 29-30)
Read section 4.1 pages 206-225; view 4.1 power point on wiki – take notes