Can you help with #12 please?

In Exercises 8- 12, determine whether the statement is true or false. If the statement is false, rewrite it as a true statement. 8./ Substituting the value of the explanatory variable for x in the equation of the least-squares regression line results in a prediction for y 9. The least-squares regression line passes through the point of averages (x, y). 10. In general, the slope of the least-squares regression line is equal to the correlation coefficient. 11. The least-squares regression line predicts the result of changing the value of the explanatory variable. 12. The y-intercept bo of a least-squares regression line has a useful interpretation only if the x-values are either all positive or all negative