Sketch the appropriate curves. A calculator may be used.

An analysis of data shows that the mean density d (in mg/cm³) of a calcium compound in the bones of women is given by d = 139.3 + 48.6 sin(0.0674x − 0.210), where x represents the ages of women (20 ≤ x ≤ 80 years). (A woman is considered to be osteoporotic if d <115 mg/cm³.) Sketch the graph.