Finding the Fourth Proportional to 12,164.89, 16,787.55 and 7,128.10

Step by Step Solution

1. Step 1: Write the proportion equation
   12,164.89 : 16,787.55 = 7,128.10 : x
2. Step 2: Convert to fraction form
   12,164.89/16,787.55 = 7,128.10/x
3. Step 3: Cross multiply
   12,164.89x = 16,787.55 × 7,128.10
4. Step 4: Simplify right side
   12,164.89x = 119,663,335.16
5. Step 5: Solve for x
   x = 119,663,335.16/12,164.89
6. Step 6: Final answer
   x = 9,836.78