Question

6. Comparing two groups

If smoking really is bad for your health, you expect that a comparison of a group of people who have quit smoking with a group that has continued to smoke will reveal that the group quitting is, on average, healthier than the group that continued.

Statement true, false or does its truth depend on unstated conditions?

Explain why. In the last case, on what conditions does it depend on and how?

Answer 1

6) the above statement is true

There is some constrain that are,

Firstly, we may consider the set of people who previously smokes and at present doesn't. Hence here we get bivariate samples.

Secondly, we may have two groups that are independent. One with continuing smoking other quit smoking. In this case we need to consider a set of questions (like, how is life now? Is there any complications?).

These are two conditions on which the design of this study depends.