Before beginning a study investigating the ability of the drug heparin to prevent bronchoconstriction, baseline values of pulmonary function were measured for a sample of 14 individuals with a history of exercise-induced asthma. The mean value of forced vital capacity (FVC) for the sample was 4.49 liters and the standard deviation was 0.83 liters. The investigators reported the following 95% confidence interval for true mean FVC: 4.49 0.48.

a.What is the point estimate of true mean FVC?

b.What is the margin of error?