The stability of given free radicals in decreasing order is
(i) `CH_(3)-overset(.)(C)H_(2)`
(ii) `CH_(3)-Coverset(.)(H)-CH_(3)`
(iii) `CH_(3)-underset(CH_(3))underset(|)overset(.)(C)-CH_(3)`
(iv) `overset(.)(C)H_(3)`

Explanation

To determine the stability of the given free radicals, we will analyze each radical based on the number of alpha hydrogens and the degree of substitution. The stability of free radicals generally increases with the number of alkyl groups attached to the carbon bearing the unpaired electron, due to hyperconjugation and inductive effects.

### Step-by-Step Solution:

1. **Identify the Free Radicals:**
- (i) `CH3-CH2•`
- (ii) `CH3-CH•-CH3`
- (iii) `CH3-C(CH3)•-CH3`
...