Finding the Fourth Proportional to 31,900.47, 47,815.46 and 13,170.18

Step by Step Solution

1. Step 1: Write the proportion equation
   31,900.47 : 47,815.46 = 13,170.18 : x
2. Step 2: Convert to fraction form
   31,900.47/47,815.46 = 13,170.18/x
3. Step 3: Cross multiply
   31,900.47x = 47,815.46 × 13,170.18
4. Step 4: Simplify right side
   31,900.47x = 629,738,214.98
5. Step 5: Solve for x
   x = 629,738,214.98/31,900.47
6. Step 6: Final answer
   x = 19,740.72