(a) Dr F. E. Tylecote, an English doctor, reported in 1927 that almost every lung-cancer patient he had known about had been a smoker. And in 1936 two more doctors (Arkin and Wagner) reported that 90% of 135 men afflicted with lung cancer were chronic smokers.   
i. In these studies what do you think was the target population?  ii. What type of quantitative studies are these? Explain. iii. If we want to determine the level of the association between smoking and lung cancer, what other information is required? Hence state what type of quantitative study is required.  
(b) How would you carry out a following type of study for investigating the relation between cigarette smoking and lung cancer? For each type of study write around 4 to 6 sentences.  
i. A case-control study ii. A cohort study