Final answer:
To round numbers to the specified significant figures, check the first digit to be dropped; if it's 5 or greater, round up the last retained digit. Examples show the rounding of various numbers to the requested significant figures.
Step-by-step explanation:
When rounding numbers to a certain number of significant figures, you need to look at the number that will be the last significant figure and then decide whether to round up or down based on the digit that follows it. Here are the examples rounded to the requested significant figures:
(a) 0.424 rounded to two significant figures is 0.42.
- (b) 0.0038661 rounded to three significant figures is 0.00387.
- (c) 421.25 rounded to four significant figures is 421.3.
- (d) 28,683.5 rounded to five significant figures is 28,684.
Keep in mind that zeros to the right of the decimal and not to the left of other digits are counted as significant figures when they come after a non-zero digit.