Linear regression Flashcards
what equation do we get from the scatterplot? (in relation to linear regression)
the linear regression equation
y = B1 x1 + B0
B1 =
B0 =
slope
Y int
what values can B1 take
any
describe simple linear regression
looks at one x variable and one y variable
what 3 factors must be satisfied
linear XY relationship
normally distributed y
equality of variances (of y over x)
how to determine whether XY relationship is linear
look at scatterplot
how to determine whether y is normally distributed
look at normal probability plot - ends shouldn’t be skwerd
how to determine whether there’s equality of variance
do residual plot
what’s a residual
Y observed - Y expected (by linear regression equation)
null hyp?
alt hyp?
null: B1 = 0
alt: B1 =/= 0
how to evaluate
get t score
use pairs - 2 df’s and two tailed distribution to find p value
find 95%CI, where B1 is the coefficient
if the X value is binary, what are it’s values
X=1 for experimental/what’s specified
X = 0 for control/what’s not specificed
define multiple linear regression
looking at multiple x variables
in general, how do we make equation?
Y = X1B1 + X2B2 … + constant
forwards stepwise linear regression?
add in most significant variable first
then enter the rest
all the statistics are cumulative
