Finding the Fourth Proportional to 21,564.38, 29,761.52 and 13,389.54

Step by Step Solution

1. Step 1: Write the proportion equation
   21,564.38 : 29,761.52 = 13,389.54 : x
2. Step 2: Convert to fraction form
   21,564.38/29,761.52 = 13,389.54/x
3. Step 3: Cross multiply
   21,564.38x = 29,761.52 × 13,389.54
4. Step 4: Simplify right side
   21,564.38x = 398,492,995.55
5. Step 5: Solve for x
   x = 398,492,995.55/21,564.38
6. Step 6: Final answer
   x = 18,479.23