Rolando Realizes That Whenever He Studies for at Least Two

question 18

Multiple Choice

Rolando realizes that whenever he studies for at least two hours immediately before a physics exam, he gets an A on the exam, but when he does not study immediately before an exam, he gets no higher than a C on the exam. He concludes that the time spent studying immediately before the exams is responsible for his improved grades. Rolando is

• A) definitely confusing correlation with causation.
• B) very probably correct in his conclusion that the time spent studying immediately before his exams is a reason for his improved grades.
• C) likely correct that there is causation, but the causation is more likely running in the opposite direction in that the improved exam grades forced him to study immediately before each test.
• D) probably misguided in that there is no apparent correlation or causation in this situation.

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Definitions:

Negative Correlation

When the value of one variable decreases as the value of the other variable increases.

Scatterplot

A type of data visualization that uses dots to represent values obtained for two different variables, one plotted along the x-axis and the other plotted along the y-axis.

Regression Equation

A statistical method represented by an equation that models the expected value of a dependent variable as a function of one or more independent variables.

Scatterplot

A type of graph used in statistics to display values for typically two variables for a set of data.