Answer:
38.701
Step-by-step explanation:
When you are adding with significant figures, you always leave the answer with as many digits after the decimal as the number which has the smallest number of digits after the decimal dot. For instance, 6.1+2.31=8.4. In this case, all of these numbers add up to 38.7018, after which you omit the at the end, leaving you with 38.701. Hope this helps, and comment if it still doesn't make sense!