1. 3.2A Least Squares Regression
(Ladies and gentlemen,
start your calculators!)

2. Homework Comments
4-step process
Make a plot!!!!!

3. Objectives:
INTERPRET a regression line
CALCULATE the equation of the least-squares regression line

5. Least Squares Regression (as seen on the formula sheet)
Note there is a difference between our TI-84 output, the textbook and what is printed on the AP Stat formula sheet

6. LSRL Formulas Given stdev and r, you could find slope
Given mean and the slope, you can find the intercept

7. Miles driven and the price of a used Honda CR-V
22000
17998
29000
16450
35000
14998
39000
13998
45000
14599
49000
14988
55000
13599
56000
69000
11998
70000
14450
86000
10998
Miles driven and the price of a used Honda CR-V

9. Results of the linear regression of miles driven vs. price

10. Let’s play with the numbers….

12. Residual = Observed − Expected Residual = Actual − Predicted
The difference between the actual value and that predicted by the regression equation
Residual = Observed − Expected
Residual = Actual − Predicted

13. List menu (2nd:Stat)
How convenient!

14. Residuals are important because:
They show us departures from the pattern (form). In this case, departures from the linear form.

17. This scatterplot represents the number of AP Statistics exams taken vs
This scatterplot represents the number of AP Statistics exams taken vs. the number of cell phones per 100 people

20. 1993 NL Statistics for MLB Team Games Won Runs Scored Atlanta 104 767
Chic Cubs 84
738
Cincinnati 73
722
Colorado 67
758
Florida 64
581
Houston 85
716 LA 81
675
Montreal 94
732
NY Mets 59
672
Philly 97
877
Pittsburg 75
707
San Diego 61
679
San Fran
103
808
St. Louis 87