Finding the Fourth Proportional to 20,935.72, 31,430.24 and 13,571

Step by Step Solution

1. Step 1: Write the proportion equation
   20,935.72 : 31,430.24 = 13,571 : x
2. Step 2: Convert to fraction form
   20,935.72/31,430.24 = 13,571/x
3. Step 3: Cross multiply
   20,935.72x = 31,430.24 × 13,571
4. Step 4: Simplify right side
   20,935.72x = 426,539,787.04
5. Step 5: Solve for x
   x = 426,539,787.04/20,935.72
6. Step 6: Final answer
   x = 20,373.78