Each word can be changed into a new one by the addition of a single letter and anagramming the resulting letters. Can you determine the letter and the new words?

1. NASTY
2. TORAH
3. CLAIM
4. HOBOES

HINT:
The added letter will appear at the end of the anagrammed word.

Answers:

The letter X can be added to each word and the resulting letters anagrammed to form new words.

1. SYNTAX
2. THORAX
3. CLIMAX
4. SHOEBOX