67. Chronic exposure to asbestos ber is a well-known health hazard. The article The Acute Effects of Chrysotile Asbestos Exposure on Lung Function

(Envir. Res., 1978: 360—372) reports results of a study based on a sample of construction workers who had been exposed to asbestos over a prolonged period. Among the data given in the article were the following (ordered) values of pulmonary compliance

(cm3/cm H2O) for each of 16 subjects eight months after the exposure period (pulmonary compliance is a measure of lung elasticity, or how effectively the lungs are able to inhale and exhale):

167.9 180.8 184.8 189.8 194.8 200.2 201.9 206.9 207.2 208.4 226.3 227.7 228.5 232.4 239.8 258.6

a. Is it plausible that the population distribution is normal?

b. Compute a 95% CI for the true average pulmonary compliance after such exposure.

c. Calculate an interval that, with a con dence level of 95%, includes at least 95% of the pulmonary compliance values in the population distribution.