Finding the Fourth Proportional to 21,123.57, 31,691.34 and 10,580.86

Step by Step Solution

1. Step 1: Write the proportion equation
   21,123.57 : 31,691.34 = 10,580.86 : x
2. Step 2: Convert to fraction form
   21,123.57/31,691.34 = 10,580.86/x
3. Step 3: Cross multiply
   21,123.57x = 31,691.34 × 10,580.86
4. Step 4: Simplify right side
   21,123.57x = 335,321,552.52
5. Step 5: Solve for x
   x = 335,321,552.52/21,123.57
6. Step 6: Final answer
   x = 15,874.28