Answer:
0.002389
Explanation:
look at the first non-zero digit if rounding to one significant figure
look at the digit after the first non-zero digit if rounding to two significant figures
draw a vertical line after the place value digit that is required
look at the next digit
if it's 5 or more, increase the previous digit by one
if it's 4 or less, keep the previous digit the same
fill any spaces to the right of the line with zeros, stopping at the decimal point if there is one
