5.22 For the example in Section 5.3.1, y = 0 at x = 10, 20, 30, 40, and y = 1 at x = 60, 70, 80, 90.

a. Explain intuitively why ˆ β =∞for the model, logit(π) = α + βx.

b. Report ˆ β and its SE for the software you use.

c. Add two observations at x = 50, y = 1 for one and y = 0 for the other.

Report ˆ β and its SE. Do you think these are correct? Why?

d. Replace the two observations in

(c) by y = 1 at x = 49.9 and y = 0 at x = 50.1. Report ˆ β and its SE. Do you think these are correct? Why?