Finding the Fourth Proportional to 31,086.80, 42,899.75 and 16,939.64

Step by Step Solution

1. Step 1: Write the proportion equation
   31,086.80 : 42,899.75 = 16,939.64 : x
2. Step 2: Convert to fraction form
   31,086.80/42,899.75 = 16,939.64/x
3. Step 3: Cross multiply
   31,086.80x = 42,899.75 × 16,939.64
4. Step 4: Simplify right side
   31,086.80x = 726,706,021.89
5. Step 5: Solve for x
   x = 726,706,021.89/31,086.80
6. Step 6: Final answer
   x = 23,376.68