Answer: the required sample size =1658944
Step-by-step explanation:
When the prior population proportion for the study is unknown , then the formula for sample size is [tex]Sample \ size = 0.25(\dfrac{z^*}{Margin\ of \ error})^2[/tex]
z-value for 99% confidence = 2.576
[tex]Sample \ size = 0.25(\dfrac{2.576}{0.001})^2\\\\=0.25(2576)^2\\\\=1658944[/tex]
Hence, the required sample size =1658944