To enable the Test class to compile successfully, the proper method associated with the Predicate functional interface must be used on line 1. The Predicate interface represents a single-argument function that returns a boolean value. The correct method in Predicate is `test`, which takes an argument and returns `true` or `false`. Hence, the statement `if(p.test(number)) {` would correctly fulfill this purpose, ensuring that the code compiles as intended.