Finding the Fourth Proportional to 21,309.89, 31,961.18 and 9,620.37

Step by Step Solution

1. Step 1: Write the proportion equation
   21,309.89 : 31,961.18 = 9,620.37 : x
2. Step 2: Convert to fraction form
   21,309.89/31,961.18 = 9,620.37/x
3. Step 3: Cross multiply
   21,309.89x = 31,961.18 × 9,620.37
4. Step 4: Simplify right side
   21,309.89x = 307,478,401.29
5. Step 5: Solve for x
   x = 307,478,401.29/21,309.89
6. Step 6: Final answer
   x = 14,428.91