![Page 1: Correlation and regression lesson 1 Introduction](https://reader036.vdocuments.site/reader036/viewer/2022081511/56649e545503460f94b4b4f1/html5/thumbnails/1.jpg)
Correlation and regression lesson 1
Introduction
![Page 2: Correlation and regression lesson 1 Introduction](https://reader036.vdocuments.site/reader036/viewer/2022081511/56649e545503460f94b4b4f1/html5/thumbnails/2.jpg)
What is this type of graph called?
A scatter diagramWhat is a line of best fit?
![Page 3: Correlation and regression lesson 1 Introduction](https://reader036.vdocuments.site/reader036/viewer/2022081511/56649e545503460f94b4b4f1/html5/thumbnails/3.jpg)
Correlation
Lines of best fit always go through the mean of both sets of data
![Page 4: Correlation and regression lesson 1 Introduction](https://reader036.vdocuments.site/reader036/viewer/2022081511/56649e545503460f94b4b4f1/html5/thumbnails/4.jpg)
Scatter diagramsScatter diagrams illustrate bivariate data that is when two variables are
compared.
On your whiteboard draw scatter diagrams to illustrate positive correlation, negative correlation and no correlation.
How well the variables fit to a straight line of best fit is the measure of correlation they exhibit.
The two types of correlation are positive and negative.
![Page 5: Correlation and regression lesson 1 Introduction](https://reader036.vdocuments.site/reader036/viewer/2022081511/56649e545503460f94b4b4f1/html5/thumbnails/5.jpg)
Drawing lines of best fit• Draw suitable axis and plot the given points• Calculate the mean for both variables• Draw the line of best fit (through the middle of the points and the mean
of both sets of data)• Use the line of best fit to make estimates
Time x 10 15 20 25 30
Weight y 5.1 4.2 3.5 3.1 2.8
![Page 6: Correlation and regression lesson 1 Introduction](https://reader036.vdocuments.site/reader036/viewer/2022081511/56649e545503460f94b4b4f1/html5/thumbnails/6.jpg)
![Page 7: Correlation and regression lesson 1 Introduction](https://reader036.vdocuments.site/reader036/viewer/2022081511/56649e545503460f94b4b4f1/html5/thumbnails/7.jpg)
![Page 8: Correlation and regression lesson 1 Introduction](https://reader036.vdocuments.site/reader036/viewer/2022081511/56649e545503460f94b4b4f1/html5/thumbnails/8.jpg)
Product Moment Correlation Coefficient (PMCC)
The product moment correlation coefficient r is a statistical measure of how well each data point lies on a straight line
It has a value between 1 (perfect positive correlation) and -1 (perfect negative correlation).
In the exam questions it is acceptable to use a calculator to find r.
![Page 9: Correlation and regression lesson 1 Introduction](https://reader036.vdocuments.site/reader036/viewer/2022081511/56649e545503460f94b4b4f1/html5/thumbnails/9.jpg)
![Page 10: Correlation and regression lesson 1 Introduction](https://reader036.vdocuments.site/reader036/viewer/2022081511/56649e545503460f94b4b4f1/html5/thumbnails/10.jpg)
Using a calculator to calculate PMCC (r)
x 1 3 5
y 3 7 11
Stats mode
Enter the data as two lists
GRPH F1 twice (should draw a scatter graph for the data)
CALC (F1
F2 which looks like a X, then F2 ( a + bx)
This should give the results a = 1, b = 2 and r = 1 the other results can be ignored
![Page 11: Correlation and regression lesson 1 Introduction](https://reader036.vdocuments.site/reader036/viewer/2022081511/56649e545503460f94b4b4f1/html5/thumbnails/11.jpg)
Matching activity
![Page 12: Correlation and regression lesson 1 Introduction](https://reader036.vdocuments.site/reader036/viewer/2022081511/56649e545503460f94b4b4f1/html5/thumbnails/12.jpg)
![Page 13: Correlation and regression lesson 1 Introduction](https://reader036.vdocuments.site/reader036/viewer/2022081511/56649e545503460f94b4b4f1/html5/thumbnails/13.jpg)
One for you to try
![Page 14: Correlation and regression lesson 1 Introduction](https://reader036.vdocuments.site/reader036/viewer/2022081511/56649e545503460f94b4b4f1/html5/thumbnails/14.jpg)