Answer
2.579e-4
Work Step by Step
Sig figs are all digits of a measured quantity. The more sig figs, the greater the precision of the measurement. To find sig figs, you count from left to right, starting at the first digit that is non zero. Additionally, 0s between two non zeroes are significant and zeroes at the end are significant, but only if the number contains a decimal place. By these rules, converting .000257870 (which has 6 sig figs) to four sig figs results in 2.579e-4
