Standard Form by Boxed Rockets

Are These Numbers in Standard Form?

71.6 \times 10^{5}

No

9.67 \times 10^{5}

Yes

6.63 \times 10^{-5}

Yes

5.28 \times 10^{-6}

Yes

6.7 \times 10^{-4}

Yes

5.28 \times 10^{6}

Yes