| Critical Reasoning Butler: September 2025 |
| September 17 | CR 1 | CR 2 |
______________________________________
CR 1 Over an extended period of time, the average seawater temperature in a region of an ocean increased by over 1 degree Celsius. During that same time, the average size of the haddock population in the region decreased by more than 25 percent. This observation led scientists to hypothesize that warmer waters favored smaller fish because their bodies were less energy intensive and better able to adapt to the warmer water. However, long-term laboratory experiments showed no changes in the average size of haddock as water temperatures were increased.
Which of the following best explains the differences between the observations in nature and those in the laboratory experiments?
(A) The measurements of fish size in the ocean were made by oceanographers, but the ones in the laboratory were made by biologists.
(B) Measurements were made more frequently in the laboratory experiments than in the ocean.
(C) A change in marine fishing regulations during the period allowed the use of nets with a more tightly spaced mesh than had previously been permitted.
(D) The population in the ocean of predators that feed on smaller haddock increased during the period.
(E) The water salinity measured in the laboratory exactly matched that of the ocean.
______________________________________
CR 2 The public service advertising campaign promoting the use of helmets has improved bicycle safety dramatically. Over the past 12 months, the number of serious bicycling injuries has been reduced by nearly 70 percent. Unfortunately, helmet usage has not reduced the number of all types of bike injuries. While serious head trauma has decreased by nearly 85 percent, broken bones now represent 20 percent of all reported bicycling injuries. This is a significant increase from last year’s 14 percent.
The reasoning in the argument is flawed because the argument does which of the following?
A. It fails to include information about any types of bicycle injuries other than head trauma and broken bones.
B. It implies that the same conclusion can result from two different sets of causes.
C. It fails to take into account any possible increase in the number of people riding bicycles over the past 12 months.
D. It presumes that an increase in the percentage of injuries involving broken bones precludes a decrease in the actual number of such injuries.
E. It ignores the fact that a 70 percent overall decrease in injuries would not allow for an 85 percent decrease in one specific type of injury.