The following data come from a study investigating a new method of measuring body composition, and give the body fat percentage (% fat), age and sex

The following data come from a study investigating a new method of measuring body composition, and give the body fat percentage (% fat), age and sex for 18 normal adults aged between 23 and 61 years (American Journal of Clinical Nutrition, 40, 834-839).  A) calculate the sum of squares for error (SSE); B) calculate the standard error of estimate; C) calculate the regression line; D) interpret the regression coefficient (what is this telling us?)