Step-by-step explanation:
[tex]9 \times {10}^{4} = 900 \times {10}^{2} \\ \\ 3 \times {10}^{2} \\ \\ \because \: 900 > 3 \\ \purple{ \boxed{ \bold{\therefore \: 9 \times {10}^{4} > 3 \times {10}^{2}}}}[/tex]