Finding the Fourth Proportional to 22,116.78, 30,521.79 and 12,687.18

Step by Step Solution

1. Step 1: Write the proportion equation
   22,116.78 : 30,521.79 = 12,687.18 : x
2. Step 2: Convert to fraction form
   22,116.78/30,521.79 = 12,687.18/x
3. Step 3: Cross multiply
   22,116.78x = 30,521.79 × 12,687.18
4. Step 4: Simplify right side
   22,116.78x = 387,235,443.65
5. Step 5: Solve for x
   x = 387,235,443.65/22,116.78
6. Step 6: Final answer
   x = 17,508.67