A group of medical researchers is investigating how artery disease affects the rigidity of the arteries. Deformity measurements are made on a sample of 14 diseased arteries, and a sample mean of x- = 0.497 is obtained, with a sample standard deviation of s = 0.0764.
(a) What is the evidence that the average deformity value of diseased arteries is less than 0.50?
(b) Construct a 99% two-sided t-interval for the average deformity value of diseased arteries.
(c) If a 99% two-sided t-interval for the average deformity value of diseased arteries is required with a length no larger than 0.10. how many additional arteries would you recommend be analyzed?