swarman wrote:
Studies show that children who watch too much television are more likely than others to become obese adults. Jacob, who is an obese adult, must have watched more television as a child than I did, since I am not obese.
Which of the following most closely parallels the logical structure above ?
Mapping the argument:
If X happens ( children watch too much television) --> then Y happens (they are more obese)
Conclusion: Y has happened (jacob is obese ) --> hence X has happened (he must have watched too much TV)
Flaws - he is suffering from some medical condition.
In short the argument is X ---> Y == Y ---> X
A. The hardware store on Main Street must have had a bigger advertisement in the Sunday paper than the hardware store around the corner had. The hardware store on Main Street sold twice as many items as the hardware store around the corner did last week, and a Sunday paper advertisement has been shown to increase the number of items sold.
X = Sunday paper ad ---> Y = increase in sales
Hence Y = sales have increased ---> X = the store must have had an Sunday ad
- Correct
B. Studies show that large dogs live shorter lives, on average, than small dogs do. Rex is a large dog and therefore might be expected to live a shorter life than Mustang, who is a small dog.
- Wrong
X = large dogs ---> Y = shorter lives
For this option to be correct: Y = Rex lived a shorter life ---> X = Rex was a large dog
C.The county superintendent stated that all schools would be canceled for the day if snowfall last night were greater than six inches. Therefore, since the snowfall was only five inches, we must be following the usual school schedule today.
- Wrong
X = if it snowed > 6 inches ---> Y = all schools would be cancelled
For this choice to be correct: Y = all schools were cancelled ---> X = hence it snowed > 6 inches
D. According to research, people with unusual musical talent do not achieve their true potential unless they are given formal lessons. Therefore Jesse, who has achieved his full musical potential without formal lessons must not have unusual musical talent.
- Wrong
There are X 1 and X2 leading to Y. Our argument only supports one "X"
E. People who like vegetables also like fruits. Elizabeth does not like fruits, so she must not like vegetables either.
- Wrong
X = People like vegetables ---> Y = people also like fruits
For this argument to be true: Y = Eli likes fruits ---> X = she also likes vegetables