Two hundred people were asked if they had read a book in the last month. The accompanying contingency table, cross-classified by age, is produced. The probability that a respondent read a book in the last month and is at least 30 years old is the closest to ________.
A) 0.12.
B) 0.33.
C) 0.46.
D) 0.88.

Question

Two hundred people were asked if they had read a book in the last month. The accompanying contingency table, cross-classified by age, is produced.  The probability that a respondent read a book in the last month and is at least 30 years old is the closest to ________.
A) 0.12. 
B) 0.33. 
C) 0.46. 
D) 0.88.

Quizplus · Accepted Answer

To find the probability that a respondent read a book in the last month and is at least 30 years old, we need to look at the intersection of the "Read a book" row and the "30 years or older" column. We can see that there are 55 people who fit this category out of a total of 200 people surveyed. Therefore, the probability is: 
P(Read a book and at least 30 years old) = 55/200 = 0.275
This is closest to answer choice B: 0.33.

Two Hundred People Were Asked If They Had Read a Book