Suppose we know that for a particular population, the proportion of those age 65 and older who smoke is 0.21.We also know that the proportion of the same population who are younger than 65 and smoke is 0.10.What proportion of the population smokes?
A) 0.021
B) 0.31
C) 0.11
D) Need more information.

Question

Quizplus · Accepted Answer

We know that the proportion of those age 65 and older who smoke is 0.21, and the proportion of those who are younger than 65 who smoke is 0.10. We can add these proportions to find the proportion of the entire population that smokes:

0.21 + 0.10 = 0.31

Therefore, the proportion of the population that smokes is 0.31, or 31%. The answer is B.

Suppose We Know That for a Particular Population, the Proportion