The key to spotting the flawed reasoning is spotting the ever so subtle shift in words the author makes in the conclusion.
The argument appears to follow what is termed the “Repeat Form” in inductive reasoning.
If X ——-> then Y
So and so are X ——-> then so and so must be Y.
But this is not exactly what is said in the passage.
If you are part of “most people who shop for groceries no more than three times a month” ———> then you and the “most people who shop…” buy frozen dinners.
In Hallston, it is true that most people shop for groceries no more than three times for month. Then based on the premise, it could be inferred that THESE people who shop for groceries no more than three times per month will buy prepared frozen dinners regularly.
However, the conclusion made is that out of ALL the people in Hallston (including those who shop for groceries no more than 3 times per month AND those who shop MORE than 3 times per month), most will buy prepared frozen dinners regularly.
The flaw made is that the conclusion should only about the subset of people: those people in Hallston who shop for groceries no more than 3 times per month.
The conclusion should not be about ALL the people in Hallston.
D makes this same error.
We have a subset of people (people who commute to work). This subset of people drives sedans.
Then the inference is applied to ALL the people in Highland County, when it should be applied to only those people who commute to work in Highland County.
I guess it could be raised to see with numbers.
Say most people who shop 3 or fewer times per month (51% of 100 people) ——-> all 51 by prepared frozen dinners.
It’s then not necessarily true that because most people in Hallston shop 3 or fewer times per month, that most of the population in Hallston buy prepared frozen dinners
Out of the 1,000 people in Hallston, most (51%) shop 3 or fewer times per month.
510 people.
So, out of these 510 people who shop 3 or fewer times per month ——-> most buy prepared frozen dinners (51% of 510 = around 260)
However, we can then not say that MOST of the entire population of Hallston buys prepared frozen dinners (we have only 260 out of 1,000)
icandoit1995 wrote:
Most people who shop for groceries no more than three times a month buy prepared frozen dinners regularly. In Hallstown most people shop for groceries no more than three times a month. Therefore, in Hallstown most people buy prepared frozen dinners regularly.
Which one of the following arguments has a flawed pattern of reasoning most like the flawed reasoning in the argument above?
(A) It is clear that most drivers in West Ansland are safe drivers since there are very few driving accidents in West Ansland and most accidents there are not serious.
(B) It is clear that John cannot drive, since he does not own a car and no one in his family who does not own a car can drive.
(C) It is clear that Fernando's friends usually drive to school, since all of his friends can drive and all of his friends go to school.
(D) It is clear that most people in Highland County drive sedans, since most people who commute to work drive sedans and most people in Highland County commute to work.
(E) It is clear that most of Janine's friends are good drivers, since she accepts rides only from good drivers and she accepts rides from most of her friends
Posted from my mobile device