Finding the Fourth Proportional to 31,107.72, 42,929.10 and 16,961.28

Step by Step Solution

1. Step 1: Write the proportion equation
   31,107.72 : 42,929.10 = 16,961.28 : x
2. Step 2: Convert to fraction form
   31,107.72/42,929.10 = 16,961.28/x
3. Step 3: Cross multiply
   31,107.72x = 42,929.10 × 16,961.28
4. Step 4: Simplify right side
   31,107.72x = 728,132,485.25
5. Step 5: Solve for x
   x = 728,132,485.25/31,107.72
6. Step 6: Final answer
   x = 23,406.81