5.4 Understanding correlations
Answer the following questions, referring to Fig. 5.8. The four correlation coefficients r are:
A: r=−0.95 | B: r=0.12 | C: r=0.75 | D: r=0.94 |
For two plots, a correlation is not suitable.
- Determine which plot corresponds to which correlation coefficient (and for which two plots a correlation coefficient is not suitable).
- Think of an example of two quantitative variables that might produce a plot with a direction similar to Plot 1.
- Think of an example of two quantitative variables that might produce a plot with a direction similar to Plot 2.
- Compute the values of R2 for each plot identified in Part 1 of this question.

FIGURE 5.8: Six different scatterplots