12) The r-statistic is calculated by dividing A) the OLS estimator by its standard error. B) the slope by the standard deviation of the explanatory variable. C) the estimator minus its hypothesized value by the standard error of the estimator. D) A and C are correct. 13) The condence interval for the sample regression function slope A) can be used to conduct a test about a hypothesized population regression function slope. B) can be used to compare the value of the slope relative to that of the intercept. C) adds and subtracts 1.96 from the slope. D) allows you to make statements about the economic importance of your estimate. 14) If the absolute value of your calculated l-statistic exceeds the critical value from the standard normal distribution, you can A) reject the null hypothesis. B) safely assume that your regression results are signicant. C) reject the assumption that the error terms are homoskedastic. D) conclude that most of the actual values are very close to the regression line. 15) Under the least squares assumptions, the OLS estimator for the slope and intercept A) has an exact normal distribution for n '9 15. B) is BLUE. C) has a normal distribution even in small samples. D) is unbiased