Finding the Fourth Proportional to 22,710.89, 31,342.52 and 12,639.21

Step by Step Solution

1. Step 1: Write the proportion equation
   22,710.89 : 31,342.52 = 12,639.21 : x
2. Step 2: Convert to fraction form
   22,710.89/31,342.52 = 12,639.21/x
3. Step 3: Cross multiply
   22,710.89x = 31,342.52 × 12,639.21
4. Step 4: Simplify right side
   22,710.89x = 396,144,723.81
5. Step 5: Solve for x
   x = 396,144,723.81/22,710.89
6. Step 6: Final answer
   x = 17,442.95