I'm quite a beginner in the field of statistics and programming languages. I've been working on my homework about multiple linear regression and I can't figure it out.
The problem is to calculate the variance of coefficients in multiple linear regression model (Var(b0), Var(b1), ...). When I apply summary function to the linear model object, all I can see is standard error of each coefficients. As far as I understood, standard error is different from standard deviation and variance.
Could the standard errors possibly mean the standard deviation of coefficients in this context, or should I use other functions to calculate the SD and Var of coefficients?
x1 <- c(195,179,205,204,201,184,210,209)
x2 <- c(57,61,60,62,61,54,58,61)
y <- c(81.4,122.0,101.7,175.6,150.3, 64.8, 92.1,113.8)
data <- data.frame("temp"=x1,"pressure"=x2,"strength"=y)
lm.str <- lm(strength ~ temp + pressure, data=data)
summary(lm.str)
