Correlation Math Example 2

Follow the full solution, then compare it with the other examples linked below.

Example 2

easy
A study finds r=−0.85r = -0.85 between hours of TV watched per day and exam scores. Interpret this value.

Solution

  1. 1
    The correlation coefficient r=−0.85r = -0.85 is given. First, interpret the sign: negative means an inverse relationship.
  2. 2
    Interpret the sign: as TV hours increase, exam scores tend to decrease.
  3. 3
    Interpret the magnitude: ∣−0.85∣=0.85|{-0.85}| = 0.85 is close to 11, indicating a strong (not just moderate) linear association.

Answer

Strong negative linear correlation\text{Strong negative linear correlation}
Correlation measures the strength and direction of a linear relationship. However, correlation does not imply causation — a third variable might explain both.

About Correlation

Correlation measures the strength and direction of the linear relationship between two quantitative variables, ranging from −1-1 to +1+1.

Learn more about Correlation →

More Correlation Examples

Example 1 medium

Given five data points [formula], compute the Pearson correlation coefficient [formula].

Example 3 medium

If [formula], what is the coefficient of determination [formula], and what does it mean?

Example 4 easy

A study finds a correlation coefficient of [formula] between height and arm span. Describe the direc

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