Finding the Fourth Proportional to 21,105.73, 31,635.81 and 13,715.49

Step by Step Solution

1. Step 1: Write the proportion equation
   21,105.73 : 31,635.81 = 13,715.49 : x
2. Step 2: Convert to fraction form
   21,105.73/31,635.81 = 13,715.49/x
3. Step 3: Cross multiply
   21,105.73x = 31,635.81 × 13,715.49
4. Step 4: Simplify right side
   21,105.73x = 433,900,635.70
5. Step 5: Solve for x
   x = 433,900,635.70/21,105.73
6. Step 6: Final answer
   x = 20,558.43