Express 0.0004720.0004720.000472 in scientific notation.
4.72×10−34.72 \times 10^{-3}4.72×10−3
4.72×10−44.72 \times 10^{-4}4.72×10−4
47.2×10−547.2 \times 10^{-5}47.2×10−5
4.72×1034.72 \times 10^{3}4.72×103