Finding the Fourth Proportional to 31,107.85, 42,911.50 and 21,553.33

Step by Step Solution

1. Step 1: Write the proportion equation
   31,107.85 : 42,911.50 = 21,553.33 : x
2. Step 2: Convert to fraction form
   31,107.85/42,911.50 = 21,553.33/x
3. Step 3: Cross multiply
   31,107.85x = 42,911.50 × 21,553.33
4. Step 4: Simplify right side
   31,107.85x = 924,885,720.30
5. Step 5: Solve for x
   x = 924,885,720.30/31,107.85
6. Step 6: Final answer
   x = 29,731.59