Before Jonas Salk Discovered a Vaccine to Prevent Polio,people Noticed

question 81

Multiple Choice

Before Jonas Salk discovered a vaccine to prevent polio,people noticed a correlation between outside temperature and the incidence of polio.Polio cases tended to occur more in the summer months than in the winter months,and the public assumed that high temperatures alone contributed to infection.As it turned out,there was a positive correlation between temperature and polio outbreaks because polio tended to be contracted in swimming pools and other places where children congregated.This illustrates which of the following? Correlations are

• A) indicative of a causal relation.
• B) variable.
• C) invalid.
• D) no guarantee of a causal relation.
• E) unreliable.

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Definitions:

Debris Flow

Downhill-flowing slurries of loose rock, mud, and other materials, and the resulting landform and sedimentary deposit; sometimes called a mudflow.

Rock Characteristics

The inherent properties of rock, including mineral composition, grain size, texture, hardness, and color, which differentiate one rock type from another.

Wind

The movement of air from areas of high pressure to areas of low pressure, resulting in weather patterns and climatic changes on Earth.

Sand Deposition

The process by which sand is laid down or deposited by wind, water, or ice, often forming beaches, dunes, and other geological structures.