This question assumes a discrete sample space in which the out possible outcomes are natural numbers.
Since there are no possible outcomes between 3 and 4, the outcomes which are greater than 3 are 4 and any number greater than 4.
Example: Toss 5 coins. Enumerate the outcomes for # of heads greater than 3. Sure: 4 or 5.
Enumerate the outcomes for the # of heads greater than or equal to 4. Sure: 4 or 5