1. An observational study is conducted to investigate the association between age and total serum cholesterol. The correlation is estimated at r = 0.35. The study involves n=125 participants and the mean (std dev) age is 44.3 (10.0) years with an age range of 35 to 55 years, and mean (std dev) total cholesterol is 202.8 (38.4).
a) Estimate the equation of the line that best describes the association between age (as the independent variable) and total serum cholesterol.
b) Estimate the total serum cholesterol for a 50-year old person.
c) Estimate the total serum cholesterol for a 70-year old person.