A Research Study Finds That 40-Year-Olds Are Better Able to Solve

question 14

Multiple Choice

A research study finds that 40-year-olds are better able to solve math problems than 80-year-olds. It is suspected that the differences in problem-solving ability result from the fact that 80-year-olds had fewer opportunities to study math and did not have access to calculators or computers. If true, the study has revealed ________.

• A) experimenter bias
• B) a placebo effect
• C) confirmation bias
• D) cohort differences

---

Definitions:

Covariance

Covariance is a measure that indicates the extent to which two random variables change in tandem. A positive covariance means that the variables tend to move in the same direction, while a negative covariance means they move inversely.

Least Squares Line

A straight line that minimizes the sum of the squares of the differences between observed and theoretical values.

Scatter Diagram

A graphical representation of two variables that shows how much one variable is affected by another by displaying data points on a horizontal and vertical axis.

Linearly Related

Describes the direct proportional relationship between two variables, where a change in one variable is associated with a consistent change in another.