A set of data has a correlation coefficient r = 0.15. Is it reasonable to use the line of best fit to make predictions from the data?

It is not reasonable to use the line of best fit to make predictions from the data.

Explanation:

A correlation coefficient of r = 0.15 means that the goodness of fit for the data from linear regression analysis is

r² = 0.15² = 0.0225.

When r²=1, it means that correlation between the dependent and independent variable is perfect, and the dependent variable can be predicted reliably.

When r²=0, it means that there is absolutely no correlation between the dependent and independent variable.

When r²>0.9, it means that reasonable correlation exists between the dependent and independent variable.

A value of r²=0.0225 is extremely low, therefore it is not reasonable to use the line of best fit to make predictions.