1. Line of Best Fit
Linear Regression

2. Entering Data : TI 30X 2nd DATA choose 2-VAR
DATA (enter data and use down arrow)
STAT VAR
Arrow over to find
a =
b =
r =
The equation of the line is y = ax + b.
Correlation Coefficient is r.
To predict use a(predict #) + b. Estimated method

3. Entering Data : TI 36X - Pro
DATA (type in data)
2nd DATA
2 VAR L1 L2 Frequency of 1 Calc
a =
b =
r =
The equation of the line is y = ax + b.
Correlation Coefficient is r.
To predict use a(predict #) + b. Estimated method
You can use the x variable button to find a and b

4. Example 1: Year 1985 1990 1995 2000 2003 Consumer Debt 585 789 1096
The table shows the total outstanding consumer debt (excluding home mortgages) in billions of dollars in selected years.
(Data is from the Federal Reserve Bulletin.)
Let x = 0 correspond to 1985.
Year
1985
1990
1995
2000
2003
Consumer Debt
585
789
1096
1693
1987
a) Find the regression equation appropriate for this data set. Round values to two decimal places.

5. Example 1: Year 1985 1990 1995 2000 2003 Consumer Debt 585 789 1096
1693
1987
Find and interpret the slope of the regression equation in the context of the scenario.
79.86 represents the increase in consumer debt each year.
Find the approximate consumer debt in 1998.
Find the approximate consumer debt in 2008.

6. Example 2:
The table below shows the number of deaths per 100,000 people from heart disease in selected years.
(Data is from the U.S. National Center for Health Statistics.)
Let x = 0 correspond to 1960.
Year
1960
1970
1980
1990
2000
2002
Deaths
559
483
412
322
258
240
a) Find the regression equation appropriate for this data set. Round values to two decimal places.

7. Example 2:
Year
1960
1970
1980
1990
2000
2002
Deaths
559
483
412
322
258
240
Find and interpret the slope of the regression equation in the context of the scenario.
-7.62 is the decrease in deaths caused by heart disease each year.
Find the approximate number of deaths due to heart disease in 1995.
Find the approximate number of deaths due to heart disease in 2008.

8. Classwork
Linear Regression