Question

As part of a study, two fabric types are tested for flammability at the National Bureau of Standards. Burn times in seconds are recorded after a paper tab is ignited on the center of a piece of fabric. Forty five (45) 3-foot-square pieces of Fabric A are burned with a mean burn time of 12.3 seconds with standard deviation of 1.1 seconds. Fifty five (55) 3-foot-square pieces of Fabric B are burned and have mean burn time of 13.6 seconds with standard deviation of 1.5 seconds. Calculate a test statistic that you could use to test the alternative hypothesis that there is a difference in mean burn time between Fabric A and Fabric B.

Answer 1

The test statistic is ,