Question: Manufacturing and Product Development A recent study was conducted to determine the curing efficiency (time to harden) of dental composites (resins for the restoration of damaged teeth) using two different types of lights. Independent random samples of lights were obtained and a certain composite was cured for 40 seconds. The depth of each cure (in mm) was measured using a penetrometer. The summary statistics for the Halogen light were n1 = 10, x¯1 = 5.35, and s1 = 0.7. The summary statistics for the LuxOMax light were n2 = 10, x¯2 = 3.90, and s2 = 0.8. Assume the underlying populations are normal, with equal variances.
a. The maker of the Halogen light claims that they produce a larger cure depth after 40 seconds than LuxOMax lights. Is there any evidence to support this claim? Use a = 0.01.
b. Construct a 99% confidence interval for the difference in population mean cure depths.