3. Interpret the slope in context for each situation. a. The average height of children ages 8 to 13 can be modeled by the equation y = 35 + 2x, where x is the age in years and y is the average height in inches. b. Researchers found that the weight of an infant less than 12 months old can be predicted using the equation y = 9.9 + 1.1x, where y is the weight in pounds and x is the age in months. www.ncbi.nlm.nih.gov/pubmed/18021105 www.ncbi.nlm.nih.gov/pubmed/18021105 c. The equation of the line that estimates the number of airports, y, a state has given its population in millions, x, is y = 6.1016 + 1.35x.