Finding the Fourth Proportional to 15,401.34, 21,253.77 and 8,689.15

Step by Step Solution

1. Step 1: Write the proportion equation
   15,401.34 : 21,253.77 = 8,689.15 : x
2. Step 2: Convert to fraction form
   15,401.34/21,253.77 = 8,689.15/x
3. Step 3: Cross multiply
   15,401.34x = 21,253.77 × 8,689.15
4. Step 4: Simplify right side
   15,401.34x = 184,677,137.95
5. Step 5: Solve for x
   x = 184,677,137.95/15,401.34
6. Step 6: Final answer
   x = 11,990.98