QUESTION 8 For a single regressor model, which of the following is a true statement? O a. by dividing the estimate by its standard error you obtain the t-statistic. O b. the square root of the F-statistic is a t-statistic. the estimate is significant (at the 5% level) if the absolute value of the t-statistic is above 1.96. the estimate is significant (at the 5% level) if the confidence interval does not contain the zero. O e. All of the above. Of. None of the above