Arguement Validity

Chapter 7 Exercise 9

2. The premise that past events guarantees future events is fallacious. Although there is an average amount of rainfall in California, the average does not represent an actual yearly amount of rainfall. Therefore the prediction for 23 inches of rain is weak, and can only be considered possibly true or possibly false.

3. The premises of the argument are that the vehicle is old, has a 'monster V8', and needs an overhaul. Each of these conditions does make it likely true that the vehicle will not achieve 40 miles per gallon. However, we do not know everything about the car; the speaker does not even divulge the make or model of vehicle, so it is possible that it might have been a uniquely fuel efficient model, or have been modified to be more fuel efficient. Therefore the conclusion is probably true, but not absolutely true.

4. The premise that past events guarantees future results is fallacious. Specifically, the premise that a victory in the Iowa Republican primary precludes a candidate from winning the party nomination, based on three out of four years of history, is worth considering, but does not absolutely guarantee history will repeat itself. However, it is true that there is a momentum to events which influences outcomes, and that there is likely some underlying but undisclosed reason for the trend in Iowa. Therefore the conclusion is probably true.

6. The conclusion that there will be a big increase in cell phones this year is probably true. Again, past history can not guarantee future results, however, unless this is the year in which the market has reached saturation, or some unanticipated, significant event occurs, it is likely that cell phone usage will continue to increase at a rapid pace.

7. This argument is a controversial one, but based on the premises that graduates from certain schools score better on tests than other schools, I would suggest that the conclusion is only possibly true or possibly...