Suppose that the regression equation y = 16.99 + 0.32 x1 + 0.41 x2 + 5.31 x3 predicts an adult's height (y) given the individual's mother's height (x1), his or her father's height (x2), and whether the individual is male (x3 = 1) or female (x3 = 0). All heights are measured in inches. In this equation, the coefficient of means that . x1; if two individuals have mothers whose heights differ by 0.32 inch, then the individuals' heights will differ by 1 inch. x1; if two individuals have mothers whose heights differ by 0.5 inch, then the individuals' heights will differ by 0.32 inch. x2; if two individuals have fathers whose heights differ by 1 inch, then the individuals' heights will differ by 0.41 inches. x2; if two individuals have mothers whose heights differ by 1 inch, then the individuals' heights will differ by 0.41 inches. x3; a brother is expected to be 5.31 inches taller than his sister