Question

1. a set of data points has a correlation coefficient r = -0.86. your friend claims that because the correlation coefficient is close to -1, it is reasonable to use the line of best fit to make predictions. is your friend correct? explain your reasoning.

Explanation:

The correlation coefficient $r$ measures the strength and direction of a linear relationship. A value of $r = - 0.86$ is close to -1, indicating a strong negative linear relationship. When there is a strong linear relationship (either positive or negative), the line of best - fit can be used to make predictions as the data points follow a linear pattern closely.

Answer:

Yes, your friend is correct. The correlation coefficient of -0.86 indicates a strong negative linear relationship, so it is reasonable to use the line of best fit for predictions.