population attributable risk............ - validation

[ArchivalUser]

In a small observational study, 100 industrial workers are followed for one year to assess for the development of respiratory symptoms (defined as productive cough lasting at least one week). 30 of 60 smokers experience respiratory symptoms over the year versus 10 of 40 non-smokers. What percentage of respiratory disease experienced by all study subjects is attributed to smoking?
A) 75%
B) 50%
C) 25%
D) 20%
E) 10%

[ArchivalUser]

.D.

[ArchivalUser]

Sorry I think it should be C.

[ArchivalUser]

docs..i do not have the answ for this qsn, could you folks explain..thanks

[ArchivalUser]

Population Attributable Risk=RR-1/RR.Here RR=2.So,Population Attributable Risk is 50%
I think I m right this time:-)