Finding the Fourth Proportional to 12,992.92, 17,931.72 and 7,689.58

Step by Step Solution

1. Step 1: Write the proportion equation
   12,992.92 : 17,931.72 = 7,689.58 : x
2. Step 2: Convert to fraction form
   12,992.92/17,931.72 = 7,689.58/x
3. Step 3: Cross multiply
   12,992.92x = 17,931.72 × 7,689.58
4. Step 4: Simplify right side
   12,992.92x = 137,887,395.48
5. Step 5: Solve for x
   x = 137,887,395.48/12,992.92
6. Step 6: Final answer
   x = 10,612.50