Finding the Fourth Proportional to 21,251.89, 31,876.62 and 8,105.59

Step by Step Solution

1. Step 1: Write the proportion equation
   21,251.89 : 31,876.62 = 8,105.59 : x
2. Step 2: Convert to fraction form
   21,251.89/31,876.62 = 8,105.59/x
3. Step 3: Cross multiply
   21,251.89x = 31,876.62 × 8,105.59
4. Step 4: Simplify right side
   21,251.89x = 258,378,812.31
5. Step 5: Solve for x
   x = 258,378,812.31/21,251.89
6. Step 6: Final answer
   x = 12,157.92