Question 10.25

10.25 Was inference justified?

You see from Figure 10.11 that the incomes of men at each age are (as expected) not Normal but right-skewed.

  1. How is this apparent on the plot?
  2. Nonetheless, your confidence interval in the previous exercise will be quite accurate even though it is based on Normal distributions. Why?

10.25

(a) For the stack at each age, there are very few with large incomes, showing the right-skew. (b) Regression inference is robust against moderate lack of Normality, especially given our large sample size.

inage