Finding the Fourth Proportional to 31,128.56, 42,954.32 and 16,981.28

Step by Step Solution

1. Step 1: Write the proportion equation
   31,128.56 : 42,954.32 = 16,981.28 : x
2. Step 2: Convert to fraction form
   31,128.56/42,954.32 = 16,981.28/x
3. Step 3: Cross multiply
   31,128.56x = 42,954.32 × 16,981.28
4. Step 4: Simplify right side
   31,128.56x = 729,419,335.13
5. Step 5: Solve for x
   x = 729,419,335.13/31,128.56
6. Step 6: Final answer
   x = 23,432.48