Regression Analysis Flashcards
1
Q
Regression
A
- One affects the other
- Cause and Effect
- X and Y cannot be changed
- Data represented by line
2
Q
Correlation
A
- Relationship
- Variables move together
- X and Y can be interchanged
- Data represented by single point
3
Q
X Variable
A
Predictor
- Independent Variable
4
Q
Y Variable
A
Response
- Dependent Variable
5
Q
Slope
A
- Statistic for every “X” we should see beta change in “Y”
ex: for every MM$ of sales (X) we will see a beta increase in units(Y)
6
Q
Y-Intercept
A
-Horsepower vs Gas Mileage
7
Q
WARNING:
Regression doesn’t PROVE CAUSE and EFFECT, but it can be used to PREDICT cause and effect
A
8
Q
SSR = Variation Explained by Regression
A
for each set of data we take the predicted (y-value - mean of actual y)^2
then we add them all up
9
Q
SSE = Variation that is Unexplained by Model
A
for each set of data we
10
Q
SST = SSR + SSE
A
total variation around the mean = variation explained by regression + unexplained or error variation
11
Q
R^2
A
R^2 is the correlation coefficient
- never have a negative coefficient of determination
