please help ASAP

Your textbook reports the following result from a two-way fixed effects (entity and time fixed effects) regression model: FR = StateFixedEffect + TimeFixedEffects - 0.64 BeerTax (0.36) Where the number in parenthesis is the heteroskedasticity- and autocorrelation-consistent (HAC) standard error. a) Calculate the t-statistic. Can you reject the null hypothesis that the slope coefficient is zero in the population, using a two- sided test and a 5% significance level? b) Given that economic theory suggests that the population slope is negative under the alternative hypothesis, is it possible to use a one-sided test here? In that case, does your conclusion change? c) Using only heteroskedasticity-robust standard errors, but not HAC standard errors, the value in parenthesis becomes 0.25. Repeat the calculations in a) and report your decision based on a two-sided test. d) Since the coefficient becomes more statistically significant in c), should this influence your choice of standard errors? Why or why not