Problem 2 (10) Consider the first order model with X1, X2 and X3, simultaneously estimate parameters (beta1, beta2, beta3) with a confidence level of 75%.

Q: What's the R code for this question (in general no specific data)?

Also when asked: "Consider only the first order model with X1, X2 and X3, perform the following hypothesis.

(10) whether X1 can be dropped from the full model"

Q: In the R code should we write anova(lm(y-x1,x2,x3)), or anova(lm(y-x2,x3,x1))

Only answer the Q: questions.