39. A sample of 25 pieces of laminate used in the manufacture of circuit boards was selected and the amount of warpage (in.) under particular conditions was determined for each piece, resulting in a sample mean warpage of .0635 and a sample standard deviation of .0065.

a. Calculate a prediction for the amount of warpage of a single piece of laminate in a way that provides information about precision and reliability.

b. Calculate an interval for which you can have a high degree of con dence that at least 95% of all pieces of laminate result in amounts of warpage that are between the two limits of the interval.