library(AER) library(MASS) mod <- lm(medv ~ lstat + crim + age, data = Boston) # construct a 99% confidence interval for all coefficients # construct a 99% confidence interval for all coefficients confint(mod, level = 0.99) test_function("confint", args = c("object", "level")) success_msg("Well done! Analogously to the previous exercise we see that 0 is not an element in any of confidence intervals but for the coefficient on the crime rate. Hence, as expected, the test decision remains the same.")