### Exercises for Chapter XVI Probable Inference

Claudio Gutierrez and Luis G. Coronado

Translated from Spanish by Inés Gutiérrez

1. Distinguish the arguments by probable inference from the strictly deductive ones.

1. If intense vaccination campaigns are developed, then certain illnesses will decrease remarkably in our country. It is so that these illnesses have decreased; therefore these vaccination campaigns were developed.

2. If taxes are raised, cost of living will increase. If cost of living increases, then the acquisitive power of the dollar will diminish. Therefore, if taxes are raised, acquisitive power of the dollar will diminish.

3. If tax reform is approved, then the fiscal problem will be resolved. It is so that the fiscal problem is not resolved; therefore, tax reform was not approved.

4. If agriculture is diversified, farmers gain more economic independence. Agriculture is diversified; therefore, farmers gain more economic independence.

5. If the remedy is adequate to fight the illness, then it will cure the patients in a few days. It is so that the patients recovered in a few days. Therefore, the remedy is adequate to fight the illness.

6. If import duties to certain foreign products are reduced, then smuggling will diminish. Smuggling does not diminish; therefore, import duties were not reduced.

7. If John is a good man, then he is fair in business. It is so that John is a good man; therefore he is fair in business.

2. Compose six arguments in such a manner that three are probable inferences and the other three are fallacious ones.

3. Make up a list of ten hypotheses, for instance from the natural sciences, and attach to each of them at least two pieces of confirming evidence.

4. In the following assertions, distinguish whether they are based on immediate or mediate knowledge.

1. Last night it rained heavily over Massachusetts.

2. I cannot accept your explanation, since it is inconsistent.

3. Since all warm-blooded animals are mammals, whales are mammals too.

4. There was a traffic accidente around the corner; I saw it.

5. The principle of universal gravitation plays an essential role in Newton’s physics.

6. The sunset was really beautiful.

7. As all these gold pieces are ductile, gold in general must be ductile.

8. The Earth turns over its own axis.

9. It is extremely cold today.

10. Since it rained heavily in the spring, the harvest will be abundant.

11. The sun is a star.

5. Indicate which of the following arguments by analogy may be considered correct.

1. This new outfit will be of excellent quality, since I bought it at the same store and it is of the same brand than the one Alice bought.

2. All students who do their homework all year around and punctually attend their classes unfailingly pass the course. Since you do the same, you most certainly will pass also.

3. I will buy my mother a new TV set at the main-street store, whose owner is extremely nice. Not at the Shopping Center, where attention is too impersonal.

4. I have no doubt that you will succeed in your professional career. You have an outstanding theoretical and practical background, a proven avocation, and great ability to interact with people. In sum, you have all the ingredients of a distinguished professional.

5. Yes: all factors of the production line are ready to go. But in all former occasions when I have succeeded as an entrepreneur I was following good astrological omens. So, we must still wait for the stars to be in favorable positions to launch this new important venture.