Question

. For each of the following inductive generalizations, underline the conclusion; specify the target group and the sample group, and answer the questions that follow each to determine whether the argument is strong or weak whether there is not enough information to decide. If there is not, specify what you would need to know to make a decision.

1) Air samples were taken from a dozen locations around the city, and all showed unhealthy levels of pollutants. Therefore, the air in the city has an unhealthy level of pollution.

Target group:

Sample group:

Is the sample group representative of the target group? Why/why not?

Is the sample group sufficiently large?

Based on your answers to the previous two questions, is the argument strong or weak, or do you not have enough information to decide?

2) I have a 2012 Chevy Sonic, and it has been very reliable. Therefore, Chevy Sonics are reliable cars.

Target group:

Sample group:

Is the sample group representative of the target group? Why/why not?

Is the sample group sufficiently large?

Based on your answers to the previous two questions, is the argument strong or weak, or do you not have enough information to decide?

3) Reputable, non-partisan polling firm conducted a survey of more than 2000 randomly chosen"adults who are eligible to vote in the next presidential election, and they found that more than half are planning to vote for the incumbent. Therefore, the incumbent will get re-elected.

Target group:

Sample group:

Is the sample group representative of the target group? Why/why not?

Is the sample group sufficiently large?

Based on your answers to the previous two questions, is the argument strong or weak, or do you not have enough information to decide?

Answer 1

1) Target Group: The entire city
Sample group: Dozen locations around the city

The sample group is representative of the target group as the sample is taken from different locations of the city.
The sample group seems sufficiently large.
The argument is strong as the sample is representative and the sample group is large enough to conclude that air in the city has an unhealthy level of pollution.

2) Target group: Chevy Sonics cars
Sample Group: Self-owned 2012 Chevy Sonic car (1 in number)

The sample group is not representative of the target group because there's only one type of model based in a single area.
Sample group is not sufficiently large enough.
The argument is weak as the sample group is small and not representative.

3) Target group: American adults
Sample Group: 2000 randomly chosen adults

Sample group is representative of the population as they are randomly chosen out of all adults.
Sample group is sufficiently large.
We need more information to decide whether the incumbent will be re-elected or not. We can't just say on the basis of the given information. We will need to conduct a proportions test.