=+13.3 Data presented in the article “Manganese Intake and Serum Manganese Concentration of Human Milk-Fed and Formula-Fed Infants” (American Journal of Clinical Nutrition [1984]: 872–878) suggest that a simple linear regression model is reasonable for describing the relationship between y 5 serum manganese (Mn) and x 5 Mn intake (mg/kg/day). Suppose that the true regression line is y 5 22 1 1.4x and that s 5 1.2. Then for a fixed x value, y has a normal distribution with mean 22 1 1.4x and standard deviation 1.2.