Finding the Fourth Proportional to 12,488.78, 18,720.41 and 5,920.49

Step by Step Solution

1. Step 1: Write the proportion equation
   12,488.78 : 18,720.41 = 5,920.49 : x
2. Step 2: Convert to fraction form
   12,488.78/18,720.41 = 5,920.49/x
3. Step 3: Cross multiply
   12,488.78x = 18,720.41 × 5,920.49
4. Step 4: Simplify right side
   12,488.78x = 110,834,017.40
5. Step 5: Solve for x
   x = 110,834,017.40/12,488.78
6. Step 6: Final answer
   x = 8,874.69