Linear Regression Flashcards
(14 cards)
Population regression Line equation
E(Y)= alpha+betaX
Linear regression model in terms of a typical observation data point i
what is the sample regression equation
Equation for b in OLS
b= Cov(X,Y)/Var(X)
Equation for a in OLS
What would an estimate of B that was 0.73 tell us
A one unit increase in the x variable is associated with 0.73 unit increase in y variable
What does an estimate of a of -55.9
It is the y intercept, so the value of y when x is zero
Simplest way to get R^2
Cov(X,y)^2/ Var(x) x Var(y)
What is the test statistic equation for hypothesis testing
TS= b/ se(b)
How to form confidence intervals for a or b
a/b +cv (T distribution) x se(a/b)
How to find critical values for confidence intervals of a or b
Use Table 3 for T distribution with n-2 degrees of freedom
What is R squared also equal to
The correlation coefficient squared
What does an R squared result of 0.77 tell us
77% of the variation in Y is explained by variation in X
What is the elasticity of Y equation
Beta x xbar/ y bar
