Finding the Fourth Proportional to 12,128.78, 18,197.50 and 4,339.82

Step by Step Solution

1. Step 1: Write the proportion equation
   12,128.78 : 18,197.50 = 4,339.82 : x
2. Step 2: Convert to fraction form
   12,128.78/18,197.50 = 4,339.82/x
3. Step 3: Cross multiply
   12,128.78x = 18,197.50 × 4,339.82
4. Step 4: Simplify right side
   12,128.78x = 78,973,874.45
5. Step 5: Solve for x
   x = 78,973,874.45/12,128.78
6. Step 6: Final answer
   x = 6,511.28