Finding the Fourth Proportional to 21,349.56, 31,981.42 and 10,643.61

Step by Step Solution

1. Step 1: Write the proportion equation
   21,349.56 : 31,981.42 = 10,643.61 : x
2. Step 2: Convert to fraction form
   21,349.56/31,981.42 = 10,643.61/x
3. Step 3: Cross multiply
   21,349.56x = 31,981.42 × 10,643.61
4. Step 4: Simplify right side
   21,349.56x = 340,397,761.73
5. Step 5: Solve for x
   x = 340,397,761.73/21,349.56
6. Step 6: Final answer
   x = 15,944.02