Finding the Fourth Proportional to 31,128.64, 42,957.12 and 16,981.18

Step by Step Solution

1. Step 1: Write the proportion equation
   31,128.64 : 42,957.12 = 16,981.18 : x
2. Step 2: Convert to fraction form
   31,128.64/42,957.12 = 16,981.18/x
3. Step 3: Cross multiply
   31,128.64x = 42,957.12 × 16,981.18
4. Step 4: Simplify right side
   31,128.64x = 729,462,587.00
5. Step 5: Solve for x
   x = 729,462,587.00/31,128.64
6. Step 6: Final answer
   x = 23,433.81