ANSWER:
Whenever p is not the same as 0.5
(Whenever p is different from 0.5)
Step-by-step Explanation:
Recall that the sample size needed will be at it's maximum when p is equal to 0.5.
Therefore, if p is equal to 0.5, i.e p=0.5 The sample size formula will yield the required sample size but whenever p is different from 0.5, using p=0.5 The sample size formula will yield a sample size larger than required to construct a confidence interval for p with a specified bound and a specified confidence level.