Concept:Leading zeros are not significant.Only digits after the first non-zero digit are counted.Explanation:In 0.002473, the significant digits are 2, 4, 7, 3.For 3 significant figures, keep 2, 4, 7.Check the next digit, which is 3.Since 3<5, the digit 7 does not round up.Thus, 0.002473 rounded to 3 significant figures is 0.00247.Answer:0.00247