I am switching my son from ready to feed formula to powdered formula (same kind). he will be 4 months on the 25th. do i need to boil water to make his formula and can bottled water be used to make it- if yes does the bottled water need to be boiled?

The site does not provide your location & the answer depends on your water supply. In the US, most city water supplies are certified and safe to use out of the tap. Those on well water or other source with no certification may need to boil water. Purified/bottled water is generally safe, again depending on the source, and boiling would not be needed.

Bottled sterile water found in the formula aisle often may be used to mix the formula. Read the instructions carefully and avoid errors in measuring. Monitor growth with your Pediatrician.