A random sample of 346 individuals is selected, and the individuals are classified according to their smoking habits and the smoking habits of their parents. The results are given in the contingency table below.
Parents' smoking habits:
Both parents smoke Only one parent smokes Neither parent smoke
Smokes 93 51 34
Does not smoke 33 40 95
Among the individuals in the sample who do not smoke, what is the relative frequency of individuals who have two parents who do not smoke?
Write your answer as a fraction.
The solution gives the details of computing relative frequency of a given data.