Self-study
Support Most people who shop for groceries no more than three times a month buy prepared frozen dinners regularly. ██ █████████ ████ ██████ ████ ███ █████████ ██ ████ ████ █████ █████ █ ██████ ██████████ ██ █████████ ████ ██████ ███ ████████ ██████ ███████ ██████████
Method of Reasoning
As shown below, this argument uses a chain of conditional claims, linked by the quantifier “most”, to conclude that most people in Hallstown regularly buy prepared frozen dinners. 
Identify and Describe Flaw
The flaw in this argument stems from an incorrect understanding of the quantifier “most”. The argument relies on an invalid argument form: we cannot conclude that most people in Hallstown buy frozen dinners regularly just because most people in Hallstown don’t shop more than 3 times a month and most people in the world who don’t shop more than 3 times a month buy frozen dinners! Let’s say there are 100 people in Hallstown, and 51 of them don’t shop more than 3 times a month. At the same time, there are 1000 people in the world who don’t shop more than 3 times a month (51 of whom live in Hallstown), and 501 of them buy frozen dinners regularly. All 51 of the Hallstown residents could belong to the group of 499 people who don’t shop more than 3 times a month, but also don’t regularly buy frozen dinners!
22.
Which one of the following █████████ ███ █ ██████ ███████ ██ █████████ ████ ████ ███ ██████ █████████ ██ ███ ████████ ██████
a
It is clear ████ ████ ███████ ██ ████ ███████ ███ ████ ███████ █████ █████ ███ ████ ███ ███████ █████████ ██ ████ ███████ ███ ████ █████████ █████ ███ ███ ████████
Wrong flaw. There could be many reasons why there are few and unserious driving accidents in West Ansland—maybe people don’t drive very often—so we can’t conclude that most drivers there are safe, given the information presented. But this isn’t the same flaw as the one in the stimulus: it’s not a misunderstanding of the quantifier “most”.
b
It is clear ████ ████ ██████ ██████ █████ ██ ████ ███ ███ █ ███ ███ ██ ███ ██ ███ ██████ ███ ████ ███ ███ █ ███ ███ ██████
No flaw. This is a valid argument: If you’re in John’s family and you don’t own a car, that means you can’t drive. John is in his family and he doesn’t own a car, so he can’t drive!
c
It is clear ████ ██████████ ███████ ███████ █████ ██ ███████ █████ ███ ██ ███ ███████ ███ █████ ███ ███ ██ ███ ███████ ██ ██ ███████
Wrong flaw. This ignores many possible scenarios—maybe Fernando’s friends walk to school because they want fresh air, or maybe they bike because they don’t have cars! But this isn’t the same flaw as the one in the stimulus: it’s not a misunderstanding of the quantifier “most”.
d
It is clear ████ ████ ██████ ██ ████████ ██████ █████ ███████ █████ ████ ██████ ███ ███████ ██ ████ █████ ██████ ███ ████ ██████ ██ ████████ ██████ ███████ ██ █████
As shown below, this argument uses a chain of conditional claims, linked by the quantifier “most,” to conclude that most people in Highland County drive sedans. It relies on a flawed understanding of the quantifier “most,” though—just because most people in Highland commute to work and most people in the world who commute to work drive sedans, does not mean that most people in Highland drive sedans! It’s the same flaw from the stimulus!
e
It is clear ████ ████ ██ ████████ ███████ ███ ████ ████████ █████ ███ ███████ █████ ████ ████ ████ ███████ ███ ███ ███████ █████ ████ ████ ██ ███ ████████
No flaw. This is a valid argument! If most of Janine’s friends are people from whom she would accept a ride, and everyone from whom Janine would accept a ride is a good driver, then most of Janine’s friends must be good drivers.