Finding the Fourth Proportional to 21,086.78, 29,102.65 and 12,134.10

Step by Step Solution

1. Step 1: Write the proportion equation
   21,086.78 : 29,102.65 = 12,134.10 : x
2. Step 2: Convert to fraction form
   21,086.78/29,102.65 = 12,134.10/x
3. Step 3: Cross multiply
   21,086.78x = 29,102.65 × 12,134.10
4. Step 4: Simplify right side
   21,086.78x = 353,134,465.37
5. Step 5: Solve for x
   x = 353,134,465.37/21,086.78
6. Step 6: Final answer
   x = 16,746.72