Finding the Fourth Proportional to 31,128.90, 42,958.24 and 16,981.98

Step by Step Solution

1. Step 1: Write the proportion equation
   31,128.90 : 42,958.24 = 16,981.98 : x
2. Step 2: Convert to fraction form
   31,128.90/42,958.24 = 16,981.98/x
3. Step 3: Cross multiply
   31,128.90x = 42,958.24 × 16,981.98
4. Step 4: Simplify right side
   31,128.90x = 729,515,972.52
5. Step 5: Solve for x
   x = 729,515,972.52/31,128.90
6. Step 6: Final answer
   x = 23,435.33