Self-study
Chemical-company employee: Support A conservation group's study of the pollutants released into the environment by 30 small chemical companies reveals that our company and four other companies together account for 60 percent of the total. ████████ ███ ███████ ████████ ████ ██████████ ████ ████ ████████ █████████ ███████ ██ ██ ██ █████
Summary
The author concludes that our company releases more pollutants than most chemical companies similar to us in size.
What makes the author think this?
Because a study of the pollutants released into the environment by 30 small chemical companies shows that our company and four others together release 60% of the total pollutants.
Notable Assumptions
The author assumes that our company’s portion of the 60% released by our company and four others together isn’t just a miniscule percentage. This overlooks the possibility that our company might just release 1 or 2% of the pollutants, but the other four together account for 58 or 59%.
4.
Which one of the following ██ ██ ██████████ ████████ ██ ███ ██████████ █████████
a
The conservation group ████ ████████ ███ █████ ██ ███ ███████ ██ ███ ████████ █████████
Not necessary, because whether the group that produced the study is biased has no bearing on the logic of the author’s argument.
b
The employee's company ████ ███ ███████ █████████ █████ ██████████ █████████ ████████ ████ ██████████ ████ ███ █████████ ████████ ██ █████ █████ ████████ ██████████
Not necessary, because whether a greater amount of pollutants are produced naturally by the chemicals processed has no bearing on whether the company releases more pollutants than most other similarly-sized chemical companies. The issue is whether the company releases more; not whether those pollutants result naturally or unnaturally.
c
The total pollution ████████ ██ ███ █████ ████████ █████████ ████████ ██ ███ ███████ ██████████ ██ ████ ████████ ██ █████ ████████ ██████████
Not necessary, because the argument concerns only small chemical companies. The author doesn’t take a position on how small companies’ pollution compares to large companies’.
d
The four other █████████ █████████ ██ ███ ████████ ██ ███ ████████ ███████ ███ ████ █████ ██ ██ ███████ ██ ███ █████ █████████ ██ ███ ██ ██████████
Necessary, because if it were not true — if the four other companies mentioned DO together account for very close to 60% of the total pollution of the 30 companies — then that implies the author’s company contributes only a minimal portion of pollutants. Then we’d have no reason to think the author’s company releases more pollutants than most other small chemical companies.
e
There is no ███████████ █████████ ██ ███ ██████████ ██ ██████████ ████████ ██ ███ █████ ██ █████ ████████ ██████████
Not necessary, because there could be a large variation in the quantities of pollution released by the other 25 small chemical companies. This doesn’t undermine the argument, because we’d still have reason to think from the study that the author’s company pollutes more than most other chemical companies. Perhaps there are one or two others that pollute much more; that’s not inconsistent with the author’s reasoning.