Finding the Fourth Proportional to 21,123.12, 31,691.98 and 12,246.16

Step by Step Solution

1. Step 1: Write the proportion equation
   21,123.12 : 31,691.98 = 12,246.16 : x
2. Step 2: Convert to fraction form
   21,123.12/31,691.98 = 12,246.16/x
3. Step 3: Cross multiply
   21,123.12x = 31,691.98 × 12,246.16
4. Step 4: Simplify right side
   21,123.12x = 388,105,176.87
5. Step 5: Solve for x
   x = 388,105,176.87/21,123.12
6. Step 6: Final answer
   x = 18,373.48