Finding the Fourth Proportional to 31,399.12, 47,088.60 and 13,868.56

Step by Step Solution

1. Step 1: Write the proportion equation
   31,399.12 : 47,088.60 = 13,868.56 : x
2. Step 2: Convert to fraction form
   31,399.12/47,088.60 = 13,868.56/x
3. Step 3: Cross multiply
   31,399.12x = 47,088.60 × 13,868.56
4. Step 4: Simplify right side
   31,399.12x = 653,051,074.42
5. Step 5: Solve for x
   x = 653,051,074.42/31,399.12
6. Step 6: Final answer
   x = 20,798.39