Finding the Fourth Proportional to 21,892.57, 30,206.18 and 13,391.60

Step by Step Solution

1. Step 1: Write the proportion equation
   21,892.57 : 30,206.18 = 13,391.60 : x
2. Step 2: Convert to fraction form
   21,892.57/30,206.18 = 13,391.60/x
3. Step 3: Cross multiply
   21,892.57x = 30,206.18 × 13,391.60
4. Step 4: Simplify right side
   21,892.57x = 404,508,962.54
5. Step 5: Solve for x
   x = 404,508,962.54/21,892.57
6. Step 6: Final answer
   x = 18,477.00