Finding the Fourth Proportional to 21,459.57, 29,615.82 and 13,508.61

Step by Step Solution

1. Step 1: Write the proportion equation
   21,459.57 : 29,615.82 = 13,508.61 : x
2. Step 2: Convert to fraction form
   21,459.57/29,615.82 = 13,508.61/x
3. Step 3: Cross multiply
   21,459.57x = 29,615.82 × 13,508.61
4. Step 4: Simplify right side
   21,459.57x = 400,068,562.21
5. Step 5: Solve for x
   x = 400,068,562.21/21,459.57
6. Step 6: Final answer
   x = 18,642.90