2.8: Practice and Exploration

1. In the chapter we postulated that “all cats are fuzzy.”. We observed that Felix is a cat and then concluded that Felix is fuzzy using a deductive argument. Now suppose that we are researching cats online and see a picture of a Sphynx cat, a breed of cat that is hairless, and is not fuzzy. Our argument has broken down. Why does our theory not work in this case, and what does this say about using a deductive argument in the scientific method?
2. As students enter a classroom the instructor of the class notices that all the students have a cell phone. When class begins the instructor remembers that they did not close their office door and hence needs to borrow a cell phone from one of the students to call the office manager of the department to ask them to close their office door. The instructor reasons that it does not matter which student they ask because they will have a cell phone. Is the instructor using a deductive or inductive argument to make this conclusion?
3. A chef is making a cake and has cracked three eggs from a carton. Each of the three eggs were good eggs and from this this chef concludes that all the eggs in the carton are good. Is the chef using a deductive or inductive argument to draw this conclusion?
4. Suppose that a chemist does an experiment in their lab showing that a certain chemical acts as a catalyst for a chemical reaction, that is, the chemical speeds up the rate of the chemical reaction. After checking their lab work to be sure they have done the experiment carefully, they order a large amount of this catalyst anticipating an increase of these chemical reactions in future experiments. Is the chemist using deductive or inductive reasoning?
5. While getting breakfast you notice that there is a sign at your favorite donut shop that states, “All of our donuts contain sugar.” You purchase a donut, and while giving it to your partner you tell them that “this donut contains sugar.” Are you using inductive or deductive reasoning to make this statement?
6. An employee at an automobile repair shop is told that one of the four tires on a pickup truck is low on air. The employee checks three of the tires and they seem fine and therefore concludes that the fourth tire is the one that is low on air. What type of reasoning is the employee using to make this conclusion?
7. On a weekend trip you and a friend hear the strains of live music and head to a local music venue. The next band comes on stage, and it is a local band that you have never seen and know nothing about. They play five songs, and all five songs are classic songs by the band The Grateful Dead. Your friend looks at you and says, “The next song will be a Grateful Dead Song.” Is your friend using inductive or deductive reasoning to make this conclusion?
8. In the evening after work you and your partner come home and notice that the lamp has been knocked over and broken. Your partner is not surprised and blames your two cats for knocking down the lamp. You, however, construct a scenario that involves intruders breaking into your house undetected, knocking over the lamp, not disturbing anything else in the house and leaving. If a bystander were to conclude that your partner is probably correct, what type of reasoning might they use to back up their conclusion?
9. During a long day at work you decide that it is time for some refreshment. You gather the quarters from your desk and head toward the closest soft drink machine. There are five people in front of you. One by one, each person inserts their money into the machine and after some pushing of buttons and an audible expression of anger from each person, they leave without their money or a refreshing soft drink. Now it is your turn. Will you put your money into the machine to attempt to get a soft drink? Why or why not? Why type of reasoning are you using in making your decision?