1. Investigating Relationships
Scatterplots and Lines of Best Fit

2. One way this is done is through scatterplots and regressions.
Data is constantly ____________ and _________ to determine if there are ______________.
One way this is done is through scatterplots and regressions.
A _________ is a graph that consists of a set of points.
collected
analyzed
relationships
scatterplot

3. approximated regression line of best fit (LOBF) curve of best fit
Sometimes, the points in a scatterplot can be ______________ by a line (or a curve). This line or curve (called a ________) may help to see if there is a relationship. Regressions can also be referred to as a ________________, or a ____________.
approximated
regression
line of best fit (LOBF)
curve of best fit

4. Generally the points should be “________” on each side of the line.
When drawing a line of best fit, the points on the scatterplot should show the trend of the data.
Generally the points should be “________” on each side of the line.
If a regression is a good fit, (points are close to the LOBF), we can make _________ by interpolating & extrapolating the data. (Reading the data off the graph)
balanced
predictions

5. To find the equation of the LOBF:
If the regression is a good fit, find the _______ of the line (or curve.)
To find the equation of the LOBF:
Calculate the ____ of the line from the graph (use any 2 points.)
Calculate the _________ the using the slope and the coordinates of one point. (If there are any breaks in the scale you must calculate the y-intercept)
equation
slope
y-intercept

6. The Correlation Coefficient:
Linear regression is a method of finding the equation of the ________________
The ________________ or _______
indicates how well the line fits the data.
If r= ___ then the line is a perfect fit. (all points are on the line)
If r= _ no linear relationship exists. (points are scattered randomly)
line of best fit (LOBF)
correlation coefficient
r-value +1

7. Homework
Do the Activity
Pg. 337 # 1, 2
Pg. 343 # 5