10.24 Inhaling affect HONC? Refer to the previous exercise.

a. Show that the test statistic for H0: m1 = m2 equals t = 11.7. If the population means were equal, explain why it would be nearly impossible by random variation to observe this large a test statistic.

b. What decision would you make about H0, at common significance levels? Can you conclude which group had higher mean nicotine dependence? How?

c. State the assumptions for the inference in this exercise.