Finding the Fourth Proportional to 123,390.10, 173,139.80 and 123,390.10

Step by Step Solution

1. Step 1: Write the proportion equation
   123,390.10 : 173,139.80 = 123,390.10 : x
2. Step 2: Convert to fraction form
   123,390.10/173,139.80 = 123,390.10/x
3. Step 3: Cross multiply
   123,390.10x = 173,139.80 × 123,390.10
4. Step 4: Simplify right side
   123,390.10x = 21,363,737,235.98
5. Step 5: Solve for x
   x = 21,363,737,235.98/123,390.10
6. Step 6: Final answer
   x = 173,139.80