How many subjects need to be enrolled in total in the study if (1) the investigators want to have a 90% chance of detecting a significant difference using a two-sided test with α = .05 and (2) it is anticipated that 5% of the enrolled subjects will not complete the study? 

Suppose another research group wishes to replicate the findings of this study. The investigators conservatively estimate that the incidence of hearing loss will be 10% in a gentamicin + placebo group and 5% in a gentamicin + ASA group and plan to enroll an equal number of subjects in each group.