1. Estimating Ages Scatter Plots

2. Oprah Winfrey

3. Jennifer Aniston

4. Brad Pitt

5. Billy Joel

6. Jamie Foxx

7. Betty White

8. Neil Patrick Harris

9. Samuel L. Jackson

10. Ray Lewis

11. Mark Zuckerberg

12. Justin Timberlake

13. Amy Schumer

14. Angelina Jolie

15. Dr. Dre

16. Cal Ripken Jr.

17. Danai Gurira

18. Katy Perry

19. Michael Jordan

20. Dane Cook

21. Mick Jagger

22. Person
Age
Oprah Winfrey 63
Justin Timberlake 36
Jennifer Aniston 48
Amy Schumer 35
Brad Pitt 53
Angelina Jolie 41
Billy Joel 67
Dr. Dre 52
Jamie Foxx 49
Cal Ripken Jr. 56
Betty White 95
Danai Gurira 39
Neil Patrick Harris 43
Katy Perry 32
Samuel L. Jackson 68
Michael Jordan 54
Ray Lewis
Dane Cook 44
Mark Zuckerberg
Mick Jagger 73

23. Scatter Plots and Least-Squares Lines
Objectives:
Create a scatter plot and draw an informal inference about any correlation between the variables
Use a graphics calculator to find an equation for the least-squares line and use it to make predictions or estimates

24. Vocabulary
Scatterplot: Is a graph showing two sets of quantitative data on a coordinate plane.
Explanatory Variable (x): is the variable that is trying to explain changes in y.
Response Variable (y): is the value obtained at a specific x-value.

25. Correlation
The main result of a correlation is called the correlation coefficient (or "r"). It ranges from -1.0 to The closer r is to +1 or -1, the more closely the two variables are related.
If r is close to 0, it means there is no linear relationship between the variables.
If r is positive, it means that as one variable gets larger the other gets larger. If r is negative it means that as one gets larger, the other gets smaller

26. no reliable correlation
negative correlation
no reliable correlation
positive correlation x y x y x y
r is close to 1
r is close to -1
r is close to 0

27. Correlation and Prediction
no reliable correlation
perfect positive correlation
perfect negative correlation x y x y x y
r = -1
r = 0
r = 1

29. Least-Squares Regression Line (LSRL)
(line that best fits the data) 2 4 6 8 10

30. Equation of LSRL

31. Example 1
Create a scatter plot for the data shown below. Describe the correlation. Then find and graph an equation for the least-squares line. x 2 3 6 7 9 12 y 14 19 22 26 32 38

32. Example 2
The table below shows the number of students enrolled in MATH 253 at CCBC in six of the last 7 semesters. The number for the third year has been misplaced. Estimate the number of students enrolled in Math 253 in the third year.
year 1 2 4 5 6 7 # 33 29 45 43 61

33. Make prediction for the height at:
Age (months)
Height (inches) 18
76.1 19 77 20
78.1 21 22
78.8 23
79.7 24
79.9 25
81.1 26
81.2 27
82.8 28 29
83.5
Make prediction for the height at:
• 21 months
• 28 months
• 20 years

34. Guess the ages of these 5 celebrities
Dr. Phil
Taylor Swift
Cristiano Ronaldo
Kevin Hart
James Patterson

35. Actual Ages Dr. Phil (66 years old) Taylor Swift (27 years old)
Kevin Hart (37 years old)
Cristiano Ronaldo (32 years old)
James Patterson (69 years old)