Finding the Fourth Proportional to 21,146.55, 31,709.89 and 12,264.40

Step by Step Solution

1. Step 1: Write the proportion equation
   21,146.55 : 31,709.89 = 12,264.40 : x
2. Step 2: Convert to fraction form
   21,146.55/31,709.89 = 12,264.40/x
3. Step 3: Cross multiply
   21,146.55x = 31,709.89 × 12,264.40
4. Step 4: Simplify right side
   21,146.55x = 388,902,713.59
5. Step 5: Solve for x
   x = 388,902,713.59/21,146.55
6. Step 6: Final answer
   x = 18,390.84