Carry out the following calculations, express the answers to the correct numbers of significant figures, and include units in the answers.
(a) $5280 \frac{\mathrm{m}}{\mathrm{km}} \times 6.2 \mathrm{~km}$
(b) $4.5 \mathrm{~m} \times 3.25 \mathrm{~m}$
(c) $2.50 \mathrm{~g} \div 8.3 \frac{\mathrm{g}}{\mathrm{cm}^{3}}$
(d) $4.70 \mathrm{~cm} \times 6.8 \mathrm{~cm} \times 2.54 \mathrm{~cm}$