Finding the Fourth Proportional to 12,691.47, 17,516.31 and 8,709.31

Step by Step Solution

1. Step 1: Write the proportion equation
   12,691.47 : 17,516.31 = 8,709.31 : x
2. Step 2: Convert to fraction form
   12,691.47/17,516.31 = 8,709.31/x
3. Step 3: Cross multiply
   12,691.47x = 17,516.31 × 8,709.31
4. Step 4: Simplify right side
   12,691.47x = 152,554,973.85
5. Step 5: Solve for x
   x = 152,554,973.85/12,691.47
6. Step 6: Final answer
   x = 12,020.28