Finding the Fourth Proportional to 21,105.56, 31,669.28 and 10,717.31

Step by Step Solution

1. Step 1: Write the proportion equation
   21,105.56 : 31,669.28 = 10,717.31 : x
2. Step 2: Convert to fraction form
   21,105.56/31,669.28 = 10,717.31/x
3. Step 3: Cross multiply
   21,105.56x = 31,669.28 × 10,717.31
4. Step 4: Simplify right side
   21,105.56x = 339,409,557.01
5. Step 5: Solve for x
   x = 339,409,557.01/21,105.56
6. Step 6: Final answer
   x = 16,081.52