Inactive Tutor answered 09/15/23
Make the assumption that the population proportion is 0.5. This maximizes the standard deviation of the sampling distribution of the sampling proportion (i.e. standard error), which is calculated as √(pq÷n).
The critical z-value for a 99% confidence interval is 2.576. You can now solve for the sample size n
2.576 = 0.01/√(0.5 × 0.5 ÷ n)
n = 16590