Finding the Fourth Proportional to 12,690.62, 17,510.58 and 7,972.17

Step by Step Solution

1. Step 1: Write the proportion equation
   12,690.62 : 17,510.58 = 7,972.17 : x
2. Step 2: Convert to fraction form
   12,690.62/17,510.58 = 7,972.17/x
3. Step 3: Cross multiply
   12,690.62x = 17,510.58 × 7,972.17
4. Step 4: Simplify right side
   12,690.62x = 139,597,353.39
5. Step 5: Solve for x
   x = 139,597,353.39/12,690.62
6. Step 6: Final answer
   x = 11,000.04