Margin of error=0.015
90%level of confidence
letter a
[tex]\begin{gathered} ME=z\cdot\sqrt[]{\frac{p\cdot(1-p)}{n}} \\ 0.015=1.645\cdot\sqrt[]{\frac{0.5\cdot(1-0.5)}{n}} \\ 0.015=1.645\cdot\sqrt[]{\frac{0.5\cdot0.5}{n}} \\ 0.015=1.645\cdot\sqrt[]{\frac{0.25}{n}} \\ n=3006.694=3007 \end{gathered}[/tex]
letter b
[tex]\begin{gathered} ME=z\cdot\sqrt[]{\frac{p\cdot(1-p)}{n}} \\ 0.015=1.645\cdot\sqrt[]{\frac{0.18\cdot0.82}{n}} \\ 0.015=1.645\cdot\sqrt[]{\frac{0.1476}{n}} \\ n=1775.1524=1776 \end{gathered}[/tex]
