Search
Create
Log in
Sign up
Log in
Sign up
Get ahead with a $300 test prep scholarship
| Enter to win by Tuesday 9/24
Learn more
Ch 9.2: Linear Regression
STUDY
Flashcards
Learn
Write
Spell
Test
PLAY
Match
Gravity
Terms in this set (11)
regression line (
line of best fit
)
the line for which the sum of the squares of the residuals is a minimum
residual (
di
)
the difference between the
observed
y-value and the
predicted
y-value (can be positive, negative, or 0)
equation of a regression line
y(hat) = mx + b
y
represents the
observed
y-value for a data point
y(hat)
represents the
predicted y-value (on a regression line)
y(bar)
represents the
average of
all y-values
x(bar)
represents the
average of
all x-values
the regression line
always passes through point
...
x(bar), y(bar)
Given a set of data and a corresponding regression line, describe all values of x that provide meaningful predictions for y
Prediction values are meaningful only for x-values in (or close to) the range of the original data.
In order to predict y-values using the equation of a regression line, what must be true about the correlation coefficient of the variables?
The correlation between variables must be significant.
Is it appropriate to use a regression line to predict y-values for x-values that are not in (or close to) the range of x-values found in the data?
It is not appropriate because the regression line models the trend of the given data, and it is not known if the trend continues beyond the range of those data.
;