1. Do Now 12/2/09 Take out HW from last night. - Punchline worksheet 7.19
Copy HW in planner.
Text p. 328, #3-6, 8-12 evens, 16 & 17 (4 graphs)
Quiz sections Friday

2. Homework Punchline worksheet 7.19
“Did You Hear About the Mathematician Who Wanted to Make a Fruit Salad, So He Bought Some Apples and Oranges?”
1) y – 2 = 4/3(x – 7)
2) y + 4 = -2/5(x – 4)
3) y = 3x + 8
4) y = 1/4x + 3/2
5) 2x + 3y = -11
6) -5x + y = 7
7) y – 7 = 2(x + 4)
8) y + 1= -3/8(x – 6)
9) y = 5/2x – 1
10) y = -1/6x + 3/2
11) -3x + 4y = 15
12) 7x + 2y = -15
13) y = 5/3x – 3
14) y = -4/9x – 40/9
15) y = -3x – 6
“AND ORDERED PEARS”

3. Objective
SWBAT make scatter plots and write equations to model data

4. Section 5.6 “Fit a Line to Data”
Scatter Plot
a graph used to determine whether there is a relationship between paired data. y x

5. Scatter plots can show trends (patterns) in the data.y y y x x x
Relatively
no correlation
Positive correlation
Negative correlation
x and y have no apparent relationship.
As y tends to increase,
x tends to increase.
As y tends to decrease,
x tends to increase.

6. Make a scatter plot of the data in the table
Make a scatter plot of the data in the table. Describe the correlation of the data. x 1 2
2.5 3
3.5 4 5 y
y-axis
The scatter plot shows a positive correlation because as x tends to increase, y tends to increase. 4 3 2 1 1 2 3 4 5 6 7
x-axis

7. Ounces of water in water bottle
Make a scatter plot of the data in the table. Describe the correlation of the data.
Minutes on treadmill 5 10 15 20 25 30 35
Ounces of water in water bottle 12 9 7 3
y-axis
The scatter plot shows a negative correlation because as minutes on the treadmill increase, ounces of water in the water bottle decreases. 12 8
Ounces of water in water bottle 4 5 10 15 20 25 30 35
x-axis
Minutes on the treadmill

8. Using a Line of Fit to Model Data
Modeling Data
When data show a positive or negative correlation, you can model the trend in the data using a
LINE OF FIT
Using a Line of Fit to Model Data .
Make a scatter plot of the data.
Decide whether the data can be a modeled by a line. (Does it have positive or negative correlation?)
Draw a line that appears to fit the data closely.
Write an equation using two points on the line. (The points do not have to be actual data pairs, but they do have to be on the line.)

9. Ounces of water in water bottle
Draw a line of fit for the scatter plot. Write an equation that models the number of ounces of water left in the water bottle as a function of minutes on the treadmill.
Minutes on treadmill 5 10 15 20 25 30 35
Ounces of water in water bottle 12 9 7 3
Write an equation using two points on the line.
y-axis 12
Use the points (5,12) and (30,4).
12 – 4 = _8_
5 – 8
Ounces of water in water bottle
Find the y-intercept. Use (5,12). 4
y = mx + b
12 = 8 (5) + b b = 68 5 10 15 20 25 30 35
x-axis
y = x + 68
Minutes on the treadmill

10. Draw a line of fit for the scatter plot
Draw a line of fit for the scatter plot. Write an equation that models the number of years since 2000 as a function student enrollment.
Years
since 2000 1 2 3 4 5 6 7 8 9
880
890
895
900
910
905
920
930
Enrollment
Enrollment at Howell Middle School South
Write an equation using two points on the line.
950
940
Use the points (4, 900) and
(6, 910).
930
910 – = _10_ = 5
6 –
920
Student enrollment
910
Find the y-intercept.
Use (4, 900).
900
y = mx + b
900 = 5(4) + b b = 880
890
880
x-axis 00 01 02 03 04 05 06 07 08 09
y = 5x + 880
year

11. 24
Homework
Text p. 328, #3-6, 8-12 evens, 16 & 17 (4 graphs)