You have collected 15 years of data for Heron Barrier Co. You are interested in how annual unemployment affects the annual sales growth of Heron. For that reason, you have estimated the following Simple Linear Regression Model: SalesGrowth Heron = a + B Unemployment + u Sales growth is in annual terms and so is unemployment. Both variables are measure in percent. Here is the output of the regression: SUMMARY OUTPUT Regression Statistics R-Square Observations 14.17% 15 Intercept Annual Unemployment Coefficients 12.00 -7.55 Standard Error 7.00 2.43 t-Stat 1.71 -3.11 1. Interpret the estimated a coefficient. 2. Interpret the sign and the magnitude of the estimated coefficient. 3. Interpret the 1-Stat of the coefficient 4. Interpret the R-Square (R) of this regression