Finding the Fourth Proportional to 22,711.68, 31,341.76 and 12,640

Step by Step Solution

1. Step 1: Write the proportion equation
   22,711.68 : 31,341.76 = 12,640 : x
2. Step 2: Convert to fraction form
   22,711.68/31,341.76 = 12,640/x
3. Step 3: Cross multiply
   22,711.68x = 31,341.76 × 12,640
4. Step 4: Simplify right side
   22,711.68x = 396,159,846.40
5. Step 5: Solve for x
   x = 396,159,846.40/22,711.68
6. Step 6: Final answer
   x = 17,443.00