Finding the Fourth Proportional to 9,075.50, 12,485.31 and 8,686.70

Step by Step Solution

1. Step 1: Write the proportion equation
   9,075.50 : 12,485.31 = 8,686.70 : x
2. Step 2: Convert to fraction form
   9,075.50/12,485.31 = 8,686.70/x
3. Step 3: Cross multiply
   9,075.50x = 12,485.31 × 8,686.70
4. Step 4: Simplify right side
   9,075.50x = 108,456,142.38
5. Step 5: Solve for x
   x = 108,456,142.38/9,075.50
6. Step 6: Final answer
   x = 11,950.43