This document contains notes from a statistics lesson. It discusses choosing the best line of fit for linear relationships by looking at residuals, which are the differences between actual and predicted y-values. The best fit line minimizes the sum of squared residuals. Knowing the residuals allows calculating the error of prediction, with smaller residuals indicating a good fit and low error. Students are instructed to work independently on an exercise applying these concepts of line of best fit and residuals.

1. Mr.Anas Lahrichi

2.  5 min
 Individual/voice level 0
 Review your notes from last session

3.  WALT : How good is our model : residuals
 How to choose best model based on residuals
 WILF : Focused work and no chattiness
 TIB : There is a variety of models and only a
few are accurate, we need to be able to
choose

4.  Apologies for not posting the Khanacademy
skills
 Quiz 4 Thursday 11th October (Lesson 11 to
Lesson 15 in statistics package)

5.  There are two types of non linear
relationships : quadratic and exponential
 Having equations to represent our models
helps to predict

6.  For linear relationships : we use a line to
model the pattern
 I want you to be able to create the equation
for this type of model
 We will learn how to choose the best line of
fit

10.  What do we mean by line of best fit ?
 Line that best models a linear relationship
(closest to most values)
 What do we mean by residuals ?
 Difference in y values between actual and
predicted values
 What are residuals used for ?
 To determine which line is the best fit
 How do we use residuals ?
 The best fit line has the sum of residuals
close to 0

11.  Hardcopy is handed out
 Individual work,voice level 0
 I will be going around for help,raise your
hand
 Take 10 minutes to do this

13.  The line of best fit to a linear relationship is
the one that has the smallest sum of squared
residuals
 min( 𝑟𝑒𝑠𝑖𝑑𝑢𝑎𝑙𝑠
2
)

14.  Knowing the residuals,we can calculate the
error of prediction
 Small residuals => Good fit => Low error in
prediction
 Big residuals => Bad fit => Big error in
prediction

17.  Answer on the worksheet handed out per group
• Listen carefully to the instructions
• Take 15 minutes to do the exercises on your own
• Stay focused
• Voice level 1 discussions (no excessive noise)
• Raise your hand quietly for questions and wait for
me to come

18. Student Warning
1
Warning 2 Demerit

19.  Do not talk unless you have
permission (Raise your hand)
 No talking back (Come see in end
of class)
 Stay focused and on task
 Respect your classmates and
teacher
 Be prepared

20.  You are expected to do your homework on the
due date (no excuses)
 Every time you miss a homework you get a
strike,after 3 your parents are informed
 Not doing your homework will negatively affect
your grade in participation and quizzes

21.  The corrected quiz as well as rubrics will be posted on
Engrade.
 An individual assesment means no discussion at all. Any
talking will result in a 0.
 If you missed a quiz/test, you are responsible to come to
office hours to retake it.
 Come see me right after class or office hours to discuss
your copy, do not bring it up inside class.
 Any copy written in pencil cannot be considered for re-
grading, use a pen.