1. Correlation and regression lesson 1 Introduction

2. What is this type of graph called? A scatter diagram What is a line of best fit?

3. Correlation Lines of best fit always go through the mean of both sets of data

4. Scatter diagrams Scatter 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.

5. 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 x1015202530 Weight y5.14.23.53.12.8

8. 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.

10. Using a calculator to calculate PMCC (r) x135 y3711 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

11. Matching activity

13. One for you to try