The answer for the first one is 4.47945205479, if you need to round that would be 4.5.
The answer for the second one is 20.4945454545, rounding will be 20.5.
The answer for the last one is 893.84, rounding will be 893.8.
If you need to round just remember 4 or less, will be rounded to 0, and 5 or more would be rounded to 10.