Introduction to chapter 9
MUST DO BEFORE NEXT CLASS
DO ASAP PLEASE!!!!!!!!!
In order to work on chapter 9, you are going to review some concepts learned in the
algebra class.
You are going to use the calculator to sketch a scatter diagram and calculate the
equation of the line that best fits the data.
All details and explanations of the meaning of what we are doing will be done in
class.
I am asking that you follow the steps outlined in the second page of this handout in
order to sketch the scatter diagrams and calculate the equation of the line that “fits” the
data.
All of this is very mechanical; it’s a matter of following steps and copying the
results from your calculator onto these pages. During class on Wednesday/Thursday we
will go over the results in order to understand the concepts of chapter 9.
Notice that we will be INTERPRETING the results in class. If you have NOT DONE
YOUR PART at home, YOU WILL BE LOST in class!!!
If you need help, ALL TUTORS IN THE MATH SCIENCE CENTER know how to do
this. It’s covered in all algebra classes. There will be no excuse to come to class without
the work done. Remember that I am also available to help you in my office.
Remember
IT’S 3 MORE WEEKS
.........OR............
3 MORE WEEKS AND ONE SEMESTER.
Print parts 2 and 3 of chapter 9 from the NOTES page in my web site and bring
them to class on Wednesday/Thursday
Read pages 495-498 in our book.
1
Instructions for sketching a Scatter Diagram and for calculating the Regression
Equation
On the next page you have the list of problems to do. Here are the instructions to
follow
Enter data
Enter the values of x into List 1
Enter the values of y into List 2
Construct the Plot
Press 2nd STAT PLOT, select plot 1, and press ENTER to turn it ON
Arrow to the first graph icon and press ENTER (this selects a scatter plot)
Arrow down and select L1 for Xlist
Arrow down and select L2 for Ylist
Arrow down and select one of the symbols for the points
Press ZOOM 9 (this opens window to see scatter plot)
Press TRACE and arrow right/left to check the coordinates of the points in the scatterplot
Find the Regression Equation
To calculate the regression equation, in the Home Screen
We are going the calculate the equation of the line that best fits the data from
Lists 1 and 2, and paste the equation on Y1
The command in your calculator should read as follows:
LinReg(ax+b) L1, L2, Y1
See steps below
To accomplish this do the following:
Press STAT, arrow to CALC, and select 4:LinReg(ax+b)
Press 2nd L1
Press “comma” (key above the key for number 7)
Press 2nd L2
Press “comma”
Press VARS
Arrow to Y-VARS
Select 1:Function (by pressing ENTER)
Select Y1 (by pressing ENTER)
Press ENTER again
This will show the regression equation in the screen of your calculator
To Graph the line along with the scatter graph
Press ZOOM 9:Zoom Stat
2
Follow the steps from page 2 to obtain the scatter-diagram and equation for each
of the following problems
Make sure you use the lists and plots as indicated below.
After you enter the data from these 3 problems do not clear the lists 1 through 6,
since we will be using them in the class on Wednesday/Thursday
Problem 1 – Chapter problem, page 496 of book –
Enter number of boats into List 1
Enter manatee death into List 2
Show equation and scatter-diagram here. Label axes with words
Problem 2- Use the data given on problem 8 page 512 of the book.
Enter the number of fires into List 3 (DO NOT CLEAR LISTS 1 AND 2!!!!)
Enter the acres burned into List 4
Turn OFF plot 1, turn ON plot 2, select the scatter diagram using lists 3 and 4
Show equation and scatter-diagram here. Label axes with words
Problem 3- Use the data given on problem 10 page 512 of the book.
Enter the HEIGHTS into List 5 (DO NOT CLEAR LISTS 1, 2, 3, 4)
Enter the WEIGHTS into List 6
Turn OFF plot 2, turn ON plot 3, select the scatter diagram using lists 5 and 6
Show equation and scatter-diagram here. Label axes with words
3