Studied by 6 people
How do you interpret r value?
There is a (w, m, s), (pos, neg), linear relationship between x and y
what is a weak correlation?
less than 0.5
what is a moderate correlation?
0.5 to 0.8
what is a strong correlation?
0.8 to 1
what is a residual?
actual - predicted
extrapolation
using model to make predictions outside range of data
Slope interpretation
On average, for every increase in one x, we predict the y to (inc, dec) by slope units
Y-int interpretation
When x variable is 0, we predict the y variable to be y-int
what point will the LSRL always go through?
x bar, y bar
how can you find b?
b = r(Sy / Sx)
all influential points are outliersā¦
but NOT all outliers are influential
what is an example of an outlier that is not influential?
an outlier in the same direction of the trend
When a residual plot has a patternā¦
a linear model will be a BAD fit
coefficient of determination
RĀ²
percent variation in the y can be explained by linear relationship between y and x
RĀ² formula
RĀ² = 1 - (SSResid / SSTotal)
Se
measures a typical amount of variability in the vertical distances from the y to the regression line
Note 
Flashcard (22)