Finding the Fourth Proportional to 9,076.50, 12,486.69 and 8,687.70

Step by Step Solution

1. Step 1: Write the proportion equation
   9,076.50 : 12,486.69 = 8,687.70 : x
2. Step 2: Convert to fraction form
   9,076.50/12,486.69 = 8,687.70/x
3. Step 3: Cross multiply
   9,076.50x = 12,486.69 × 8,687.70
4. Step 4: Simplify right side
   9,076.50x = 108,480,616.71
5. Step 5: Solve for x
   x = 108,480,616.71/9,076.50
6. Step 6: Final answer
   x = 11,951.81