Finding the Fourth Proportional to 31,043.90, 42,890.68 and 21,654.38

Step by Step Solution

1. Step 1: Write the proportion equation
   31,043.90 : 42,890.68 = 21,654.38 : x
2. Step 2: Convert to fraction form
   31,043.90/42,890.68 = 21,654.38/x
3. Step 3: Cross multiply
   31,043.90x = 42,890.68 × 21,654.38
4. Step 4: Simplify right side
   31,043.90x = 928,770,814.59
5. Step 5: Solve for x
   x = 928,770,814.59/31,043.90
6. Step 6: Final answer
   x = 29,917.99