Finding the Fourth Proportional to 12,171.60, 16,801.56 and 7,981.20

Step by Step Solution

1. Step 1: Write the proportion equation
   12,171.60 : 16,801.56 = 7,981.20 : x
2. Step 2: Convert to fraction form
   12,171.60/16,801.56 = 7,981.20/x
3. Step 3: Cross multiply
   12,171.60x = 16,801.56 × 7,981.20
4. Step 4: Simplify right side
   12,171.60x = 134,096,610.67
5. Step 5: Solve for x
   x = 134,096,610.67/12,171.60
6. Step 6: Final answer
   x = 11,017.17