Question

Ms. Jones, a bookstore owner, wishes to send out an advertisement to potential customers. She estimates that 20 percent of the town’s residents are recreational readers, and she knows that all of the residents are either recreational readers or TV addicts (but not both). Also, a TV repair person has told her that two of ten TV addicts are newspaper subscribers, and from a survey of her own customers she has learned that seven of ten recreational readers are newspaper subscribers. If Ms. Jazzy places an ad in the local newspaper, how effective will the ad be? (That is, what is the probability that a newspaper subscriber is a recreational reader?)

A. 20%
B. 35%
C. 40%
D. 70%

Answer 1

The ad placed in the local newspaper will be 70% effective in reaching recreational readers. Thus, the ad placed in the local newspaper will be 70% effective in reaching recreational readers.

Step-by-step explanation:

To determine the effectiveness of the ad, we need to find the probability that a newspaper subscriber is a recreational reader.

Given that all residents are either recreational readers or TV addicts, and the percentage of recreational readers is 20%, we can infer that the percentage of TV addicts is 100% - 20% = 80%.

From the survey results, we know that 7 out of 10 recreational readers are newspaper subscribers.

Therefore, the probability that a newspaper subscriber is a recreational reader is 7/10 = 0.7.

Thus, the ad placed in the local newspaper will be 70% effective in reaching recreational readers.