Inductive And Deductive
nductive or deductive
This assignment has two parts.
Arguments can be inductive or deductive. Review the definitions of these two types.
For Part 1, do the following:
- Determine whether the following arguments are deductive or inductive.
- Identify the conclusion in each argument.
- Identify which of the four tests you used to make the decision.
- All birds can fly. Penguins are birds. So, penguins can fly.
- If it rained, then the streets are wet. The streets are wet. So, it rained.
- Most teenagers sleep late on weekend mornings. May is eighteen years old so May probably sleeps late on Saturday mornings.
- Every student that was in class today was given a copy of the syllabus. George is a student and was in class today so George was given a copy of the syllabus.
- Every student that was in class yesterday was given a copy of the syllabus. George is a student and was given a copy of the syllabus so George probably has the syllabus with him now.
- Yale University is an Ivy League school and has an outstanding library. Harvard University is an Ivy League school and has an excellent library. Princeton University is an Ivy League school; therefore Princeton must have a good library, too.
- John’s home address is 47 Riverside Drive. It follows that he must live near a river.
- August is always hot at Disney World in Orlando. We will be at Disney World on August 15 so it will be hot.
- Dr. Oz says there are health benefits to eating spinach. I read an article in Reader’s Digest that said spinach is good for your health. I think I should start eating spinach for better health.
- Jack put the cat outside before he went to bed. When he woke up, the cat was sleeping on his bed. Someone must have let the cat inside.
- Polls show that 75% of Democrats favor legalizing gay marriage. Arnold is a Democrat. Therefore, Arnold probably is in favor of legalizing gay marriage.
- Jennifer is a pediatrician. All pediatricians are doctors. Jennifer is a doctor.
Here are four arguments. Each is a mystery for you to solve. The solution to the mystery will be the conclusion to the argument.
For Part 2, do the following:
- For each argument, write the conclusion.
- Identify the argument as either inductive or deductive.
- Explain the steps that led to the conclusion.
- Either Abraham or Mason was the murderer. If Mason had been the murderer, he would have used a gun. The victim was stabbed. Therefore, ___________ is the murderer.
- The murder did not occur in the dining room. If Thomas was the murderer, he used a rope as a weapon. If Jackson was the murderer, he used a gun. Either Thomas or Jackson had to be the murderer. If Jackson was the murderer, then the murder took place in the dining room.
Therefore, ___________ is the murderer and the weapon was a ____________.
- The murder was not committed on the beach. If William was the murderer, the weapon was a rope. Either William or Carl was the murderer. If the weapon was a rope, then the murder was committed on the patio. If Carl was the murderer, then the weapon was a crowbar. If the weapon was a crowbar, then the murder was committed on the beach. Therefore, ____________ is the murderer, the weapon was ____________, and the murder took place on the ____________.
- Either Mr. Greene, who is the butler, or Colonel Brown killed Ruby Rose. Whoever disappeared with May White did not commit the murder. The butler ran off with May White. Therefore, _______ killed Ruby Rose.