Finding the Fourth Proportional to 31,436.02, 47,121.09 and 12,729.34

Step by Step Solution

1. Step 1: Write the proportion equation
   31,436.02 : 47,121.09 = 12,729.34 : x
2. Step 2: Convert to fraction form
   31,436.02/47,121.09 = 12,729.34/x
3. Step 3: Cross multiply
   31,436.02x = 47,121.09 × 12,729.34
4. Step 4: Simplify right side
   31,436.02x = 599,820,375.78
5. Step 5: Solve for x
   x = 599,820,375.78/31,436.02
6. Step 6: Final answer
   x = 19,080.67