Finding the Fourth Proportional to 21,255.12, 29,337.12 and 12,870

Step by Step Solution

1. Step 1: Write the proportion equation
   21,255.12 : 29,337.12 = 12,870 : x
2. Step 2: Convert to fraction form
   21,255.12/29,337.12 = 12,870/x
3. Step 3: Cross multiply
   21,255.12x = 29,337.12 × 12,870
4. Step 4: Simplify right side
   21,255.12x = 377,568,734.40
5. Step 5: Solve for x
   x = 377,568,734.40/21,255.12
6. Step 6: Final answer
   x = 17,763.66