A study by Thienprasiddhi et al. (A-4) examined a sample of 16 subjects with open-angle glaucoma and unilateral hemifield defects. The ages (years) of the subjects were:

62 62 68 48 51 60 51 57 57 41 62 50 53 34 62 61 Source: Phamornsak Thienprasiddhi, Vivienne C. Greenstein, Candice S. Chen, Jeffrey M. Liebmann, Robert Ritch, and Donald C. Hood, “Multifocal Visual Evoked Potential Responses in Glaucoma Patients with Unilateral Hemifield Defects,” American Journal of Ophthalmology, 136 (2003), 34–40.

Can we conclude that the mean age of the population from which the sample may be presumed to have been drawn is less than 60 years? Let a ¼ :05.