1. Suppose that you estimated a linear regression on birthweight in grams using different characteristics and found the following coefficients (in parentheses) all significant at traditional levels: Age (15.4), Cigarette Smoking (-132.6), Black Race (-45.3).
   1. Interpret each of these coefficients.
   2. How would you interpret a coefficient for smoking of 0.043 with a standard error of 0.01 if the dependent variable was whether or not the baby was born low birth weight? Note: the dependent variable is a dummy variable with the value for 0 if born normal weight and 1 if born LBW)
   3. What is the t-ratio for the information provided in part b? Do you think the estimated coefficient is significant at traditional levels? Why?