Answer :

I guess the working will depend upon how you're supposed to deal with fractions/decimals, but 1 = 10/10, so 4 = 40/10. 

0.0987 rounded to the closest 1/10 or 0.1 is simply 0.1, so the final answer is 4.1 or 41/10.

There are many ways of working to this answer though. 
iGreen
4.0987 rounded to the nearest tenth.

4.0987
   ^ This is the tenths place

Look at the number after it, if it's 5 or more, round up, if it's 4 or less, round down.

It's 9, so we round up to 4.1