Practice - Scientific Notation, Rounding, and Significant Figures

3. The diameter of the earth at the equator is 7,926.381 miles.
   1. Round this measurement to four significant figures. Answer: 7,926 or 7.926 x 10³
      
   2. Round this measurement to two significant figures.Answer: 7,900 or 7.9 x 10³
      
   3. Round this measurement to six significant figures. Answer: 7,926.38 or 7.92638 x 10³
      
   4. Express this measurement in scientific notation. Answer: 7.926381 x 10³
      
   5. Convert this measurement to kilometers. Express the result in scientific notation.
      
      Answer (Note that all of the conversion factors used below are exact.):
      7,926.381 miles x (5280 ft/mi) x (12 in/ft) x (2.54 cm/in) x (1 m /100 cm) x (1 km /1000 m) = 1.275627 x 10⁴ km