1) (a) the diameter of Earth at the equator is 7926.381 mi. Round this number to three significant figures, and express it in standard exponential notation. (b) the circumference of Earth though the poles is 40,008 km. Round this number to four significant figures, and express it in standard exponential notation.
2) Carry out the following operations, and express the answer with the appropriate number of significant figures. (a) 320.5 - (6104.5/2.3) . (d) 863 x [1255 - (3.45 x 108)]?