Self-study
Researcher: Support Hard water contains more calcium and magnesium than soft water contains. █████ █████ ███ █████ ██████ ████ █████ █████ ██ █████████ ████ ██ █████ ████████ ███████ ███ █████████████ ███ ██████ █████ ███████ ███ █████ ██████████ ████ ██ ████ █████ ██████ ██ █████████ ██ █████ ██████
Summarize Argument: Phenomenon-Hypothesis
The researcher hypothesizes that people who drink mostly soft water have a higher risk of heart disease, stroke, and hypertension than people who drink mostly hard water. This is because hard water has more magnesium than soft water. The researcher’s hypothesis is based on the phenomenon that people being treated for the aforementioned conditions having lower levels of magnesium in their blood.
Notable Assumptions
The researcher assumes that the difference in hard and soft water’s magnesium levels is not negligible. The researcher also assumes that lower levels of magnesium (at least in part) caused people to develop heart disease, stroke, and hypertension, as opposed to the low magnesium levels being an effect of these conditions.
17.
Which one of the following, ██ █████ ████ ██████████ ███ ████████████ █████████
a
Magnesium deficiency is ███ █████████ ████ ██ ██████████ ██████████ █████████ ████ ██ █████████ █████████ ████████ █████
This does not affect the argument. The researcher does not discuss magnesium deficiencies: he focuses on the relative magnesium levels in hard and soft water, and the low magnesium levels in the blood of people receiving treatment. We cannot conclude that they are deficient.
b
Magnesium is needed ██ ███████ ██████ ████ ██████████ █████ █████████
This does not affect the argument. The role of magnesium in maintaining blood pressure is not relevant to the argument.
c
As people age, █████ ███████ ██ ██████████ █████████ █████████████
This does not affect the argument. We don’t know about the ages of the patients being treated or how age affects one’s likeliness to develop one of the mentioned conditions.
Failed alternate explanation
Failed alternate explanation
Weaken Qs: Answers that try to introduce an alternate explanation, but fall short, or try to explain a different phenomenon.
Strengthen Qs: Answers that try to eliminate an alternate explanation, but fall short, or try to eliminate an explanation for a different phenomenon.
d
The ingestion of █████████ ███████████ ████████ ███ █████████████ ██ ████ █████████ ████ ██ █████ ████ █████ ████████ ███ █████ ████████
This does not affect the argument. (D) suggests those being treated for these conditions cannot take supplements to increase their low magnesium levels. This is compatible with the author’s assumption that lower levels of magnesium increase one’s risk of the conditions described.
Failed alternate explanation
Failed alternate explanation
Weaken Qs: Answers that try to introduce an alternate explanation, but fall short, or try to explain a different phenomenon.
Strengthen Qs: Answers that try to eliminate an alternate explanation, but fall short, or try to eliminate an explanation for a different phenomenon.
e
Compounds commonly used ██ █████ ████████████ ███ █████ ███████ ████████ ███ ██████ ████████ ██ ██████ ███ ██████ ██████████
This weakens the argument. It exploits the researcher’s assumption that lower magnesium levels caused people to need treatment for the conditions described. (E) says the opposite: that the lower magnesium levels are a result of receiving treatment.
Alternate explanation
Alternate explanation
Weaken: Introduce or support an alternate explanation for a phenomenon.
Strengthen: Helps to eliminate an alternate explanation for a phenomenon.