Finding the Fourth Proportional to 21,118.10, 29,140.10 and 12,618.43

Step by Step Solution

1. Step 1: Write the proportion equation
   21,118.10 : 29,140.10 = 12,618.43 : x
2. Step 2: Convert to fraction form
   21,118.10/29,140.10 = 12,618.43/x
3. Step 3: Cross multiply
   21,118.10x = 29,140.10 × 12,618.43
4. Step 4: Simplify right side
   21,118.10x = 367,702,103.25
5. Step 5: Solve for x
   x = 367,702,103.25/21,118.10
6. Step 6: Final answer
   x = 17,411.70