Abstract
Based on the goodness of fit approach, a new test is presented for testing exponentiality against the unknown age (used better than aged in convex ordering (UBAC)) Class of life distributions. The percentiles of this test are tabulated for sample sizes n=5(5)40. It is shown that the proposed test is simple, has high relative efficiency for some commonly used alternatives and enjoys a good power. An example in medical science is considered as a practical application of the proposed test. Copyright © 2011 John Wiley & Sons, Ltd.