Approximate each number using a calculator. (a) 2.73.1 (b) 2.713.14 (c) 2.7183.141 (a) 2.7.1 (Round to three decimal places as needed.) (b) 2.713.14 (Round to three decimal places as needed.) (c) 2.7183.141 (Round to three decimal places as needed.) (d) e (Round to three decimal places as needed.) (d) e I