The chances that tropical storms will develop in a given area increase whenever the temperature of a large body of wa...
ShirnelMarch 12, 2020
Diagramming help
Please help me diagram this, I chose A however I want to be sure that I followed this set of facts correctly.
The chances that tropical storms will develop in a given area increase whenever the temperature of a large body of water in that area exceeds 26 degrees Celsius to a depth of about 60 meters.
>26D60M ==> CTSI
not CTSI ==> not >26D60M
If the amount of carbon dioxide in the Earth's atmosphere continues to increase, the temperatures of all of the Earth's waters will rise, with the result that the number of large bodies of water whose temperatures exceed 26 degrees Celsius to a depth of about 60 meters will eventually be greater than it is today.
CDI ==> TEWR
not TEWR ==> not CDI
TEWR ==> >26D60M
not >26D60M ==> not TWER
Sufficient and Necessary Chain
CDI ==> TEWR ==> >26D60M==> CTSI
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That is exactly right. You seem to be getting the hang of these must be true questions.
It is good that you are being very thorough and writing all of your contrapositives. This is good practice until you are extremely comfortable with sufficient and necessary reasoning. This is how it is taught in the lessons. Eventually, you will be able to see when a contrapositive is going to be useful and when it is not.
For now, you are absolutely doing the right thing. I just wanted to give you an idea of what it will be like when you are a master of conditional reasoning. You will be see contrapositives automatically just by looking at your diagram. Then you can write it down if you think that it will help you.
Also, just to make things simpler for yourself, I might have combined your second and third premises. You could see it as one premise or two, but I would just write one because the relationship is pretty clear.
CDI - -> >26D60M
I'm not criticizing your approach to this question, you did everything right and got to the right answer. I just wanted to explain how you can pick up some speed as you become automatic with your sufficient and necessary reasoning.
ShirnelMarch 15, 2020
That's very helpful. Thank you.
RaviMarch 19, 2020
@Shirnel, let us know if you have any other questions!
