Finding the Fourth Proportional to 21,105.43, 31,665.37 and 7,961.56

Step by Step Solution

1. Step 1: Write the proportion equation
   21,105.43 : 31,665.37 = 7,961.56 : x
2. Step 2: Convert to fraction form
   21,105.43/31,665.37 = 7,961.56/x
3. Step 3: Cross multiply
   21,105.43x = 31,665.37 × 7,961.56
4. Step 4: Simplify right side
   21,105.43x = 252,105,743.18
5. Step 5: Solve for x
   x = 252,105,743.18/21,105.43
6. Step 6: Final answer
   x = 11,945.07