To find all combinations of four numbers from the set {200, 245, 290, 300, 360, 390, 405, 405, 435, 440, 442, 525, 545, 680} that sum to 1675, we need to check each possible set of four numbers and verify whether their sum equals 1675.

By analyzing, the valid combinations are:

1. 405, 405, 435, 430
   (405 + 405 + 435 + 430 = 1675)

2. 200, 525, 545, 680
   (200 + 525 + 545 + 680 = 1675)

If you need additional combinations or further details, let me know!

Would you like any more details or help with further calculations? Here are some related questions:

1. How can I solve problems involving combinations of numbers programmatically?
2. Can I apply this concept to different sets of numbers?
3. What are the steps involved in solving a sum combination problem manually?
4. How does this method relate to other problem-solving techniques like dynamic programming?
5. What is the difference between combinations and permutations in mathematics?

Tip: For large sets, solving sum-combination problems can be easier using computer programs like Python's itertools.combinations.