Self-study
Because of increases in the price of oil and because of government policies promoting energy conservation, the use of oil to heat homes fell by 40 percent from 1970 to the present, and many homeowners switched to natural gas for heating. ███████ █████████ ██ ███████ ███ ████████ █████████ ██ ██████████ █ ███████████ ██████ ████ ██ ███ ██ ███ ████ ██████ ██ █████████
Summarize Argument
The author claims that homeowners are generally unlikely to switch back to oil heating soon after having switched to natural gas due to its lower cost. Why? Because switching to gas in the first place required investing in new equipment, and presumably homeowners won’t want to duplicate that investment.
Notable Assumptions
The author assumes that the amount saved by continuing to use gas and not having to buy new oil-compatible equipment outweighs any savings from switching back to oil. In other words, equipment and oil have not gotten so much cheaper (and that gas hasn’t gotten so costly) that it would be worth switching again.
9.
The prediction that ends the ███████ █████ ██ ████ █████████ ██████ ████ ████████ ██ ██ ████ ████ ████ ██ ███ ████ ███ █████
a
the price of ███████ ███ ██ ████ █████ ███ ████████ █████████ █████ ███ ████ ██ █████████ ██ ████ █████ ████ ███████ ███ ███ ██████ ███████
This does not weaken the argument, because it doesn’t challenge the author’s cost-benefit assumption. This gives us no reason to believe that oil heating now represents a cost savings over gas heating—we still don’t know which one is currently cheaper.
b
the price of ████ ███████ ███ ███ ████████ █████████ █████ ███ ████ ██ █████████ ██ ████ █████ ████ ███████ ███ ███ █████ ███████
This does not weaken the argument because it doesn’t indicate any kind of savings from switching back to oil. We’re only concerned with homeowners who currently use gas, so the cost of switching to gas is irrelevant. This also doesn’t tell us how oil and gas prices compare.
c
the cost of █████████ ██ ████ █████ ████ ███████ ███ ███ ██████ ████████ █████ ███ █████ ██ ████ ███████ ███ ███ ██████ ██ ████ ██████
This does not weaken the argument. We’re not concerned with gas heating equipment prices, because we only care about current gas users. Like (E), the falling cost of oil is tempting, but we still don’t know how it compares with gas—maybe they both fell, and gas is still cheaper.
d
the cost of █████████ ██ ████ █████ ████ ███ ███ ██████ ████████ █████ ███ █████ ██ ███████ ████ ███ ███ ██████ █████ ███ █████ ██ ███████ ████ ███████ ███
This weakens the argument because it indicates that oil is currently less expensive than gas, while also reducing the additional cost of getting new oil-heating equipment. This undermines the author’s cost-benefit assumption, thereby weakening.
e
the use of ███ ██ ████ █████ ███ █████████ ██ ████████ █████ ███ █████ ██ ███████ ███ ███ ██████ ██ ████ ██████
This does not weaken the argument, because like (C), just knowing that the cost of oil has fallen doesn’t actually tell us much: we still don’t know how oil and gas compare. The continued decline in oil heating also doesn’t do anything, because we don’t know why it’s happening.